為什么我花在二分搜索上的時間比線性搜索多？

Question

我對進行二進制搜索的代碼有疑問。 據我所知，二進制搜索比線性搜索更快。 我在 leetcode 上有一個任務，我必須在其中執行二分搜索，但我收到一個超出時間限制 (TLE) 的錯誤

int search(int* nums, int numsSize, int target){
int m = 0;
int l = 0;
int r = numsSize - 1;
do{
    m = r - (r - l) / 2;
    if(nums[m] < target) r = m + 1;
    else l = m - 1;
}
while ((l <= r) && (nums[m] != target));
return m;
}

當我進行線性搜索時，我沒有收到錯誤

Answer 1

你的 function 壞了。

我下載了它，構建了一個測試程序，然后運行了它。 最終， m會卡在錯誤的索引上，function 會無限循環。

我創建了一個可以正常工作的修改版本。

改變：

m = r - (r - l) / 2;

進入：

m = l + (r - l) / 2;

在下面的代碼中，有三個函數：

orig你的原始代碼
flat ——線性搜索
fix1 -- 原始代碼 + 修復

使用/不-DORIG編譯：

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define sysfault(_fmt...) \
    do { \
        printf(_fmt); \
        exit(1); \
    } while (0)

struct fnc {
    int (*fnc)(int *nums, int numsSize, int target);
    const char *tag;
    double elap;
};

int capacity = 0;
int *buf = NULL;

int
orig(int *nums, int numsSize, int target)
{
    int m = 0;
    int l = 0;
    int r = numsSize - 1;

    do {
        m = r - (r - l) / 2;
        if (nums[m] < target)
            r = m + 1;
        else
            l = m - 1;
    } while ((l <= r) && (nums[m] != target));

    return m;
}

int
flat(int *nums, int numsSize, int target)
{
    int m = 0;
    int r = -1;

    for (;  m < numsSize;  ++m) {
        if (nums[m] == target) {
            r = m;
            break;
        }
    }

    return r;
}

int
fix1(int *nums, int numsSize, int target)
{
    int m;
    int l = 0;
    int h = numsSize - 1;

    do {
        m = l + (h - l) / 2;
        if (nums[m] < target)
            l = m + 1;
        else
            h = m - 1;
    } while ((l <= h) && (nums[m] != target));

    return m;
}

struct fnc fnclist[] = {
    { .fnc = flat, .tag = "flat" },
    { .fnc = fix1, .tag = "fix1" },
#if ORIG
    { .fnc = orig, .tag = "orig" },
#endif
    { .fnc = NULL },
};

double
tscgetf(void)
{
    struct timespec ts;
    double sec;

    clock_gettime(CLOCK_MONOTONIC,&ts);

    sec = ts.tv_nsec;
    sec /= 1e9;
    sec += ts.tv_sec;

    return sec;
}

int
xrand(int mod)
{
    int val = rand();
    val %= mod;
    return val;
}

void
dofnc(struct fnc *fnc,int *buf,int count,int idxexp)
{
    double tscbeg;
    double tscend;

    tscbeg = tscgetf();
    int idxact = fnc->fnc(buf,count,buf[idxexp]);
    tscend = tscgetf();

    tscend -= tscbeg;
    printf("%.9f %s %d/%d %d\n",tscend,fnc->tag,idxexp,idxact,count);
    if (idxact != idxexp)
        sysfault("dofnc: fault\n");
}

void
dotest(void)
{

    int count = xrand(10000) + 1;

    if (count > capacity) {
        capacity = count;
        buf = realloc(buf,sizeof(buf) * capacity);
    }

    int val = 0;
    for (int idx = 0;  idx < count;  ++idx) {
        int dta = xrand(100);
        val += dta;
        buf[idx] = val;
    }

    int idxexp = xrand(count);

    printf("\n");
    printf("count=%d\n",count);
    for (struct fnc *fnc = fnclist;  fnc->fnc != NULL;  ++fnc)
        dofnc(fnc,buf,count,idxexp);
}

int
main(void)
{

    setlinebuf(stdout);

    for (int tstno = 1;  tstno <= 10;  ++tstno)
        dotest();
}

這是程序 output（沒有-DORIG編譯）。

當使用-DORIG編譯時，原始文件掛起（我們只得到flat和fix1輸出）。

從時間上看，對於大多數大計數，二分搜索顯然比線性搜索快。


count=9384
0.000006721 flat 2253/2253 9384
0.000000241 fix1 2253/2253 9384

count=5993
0.000003500 flat 1324/1324 5993
0.000000181 fix1 1324/1324 5993

count=8955
0.000001280 flat 426/426 8955
0.000000200 fix1 426/426 8955

count=340
0.000000076 flat 7/7 340
0.000000157 fix1 7/7 340

count=1964
0.000003769 flat 1298/1298 1964
0.000000195 fix1 1298/1298 1964

count=21
0.000000103 flat 17/17 21
0.000000108 fix1 17/17 21

count=4228
0.000011880 flat 4139/4139 4228
0.000000209 fix1 4139/4139 4228

count=7858
0.000006904 flat 2398/2398 7858
0.000000231 fix1 2398/2398 7858

count=8963
0.000001663 flat 537/537 8963
0.000000218 fix1 537/537 8963

count=6304
0.000001787 flat 556/556 6304
0.000000282 fix1 556/556 6304

更新：

這是一個版本：

通過為SIGALRM設置信號處理程序並使用alarm和sigsetjmp和setlongjmp添加超時。
計算clock_gettime調用的開銷（來自tscgetf ）。
將每個測試運行 3 次，並使用最佳 [最低] 時間來考慮任何系統開銷/時間片。
選擇要搜索的隨機索引/值。
選擇低於最小數組值的值（應該失敗）。
選擇高於最大數組值的值（應該失敗）。
測試隨機數組大小。
測試 1 到 100（乘以 3）范圍內的數組大小。

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <setjmp.h>

#define sysfault(_fmt...) \
    do { \
        printf(_fmt); \
        exit(1); \
    } while (0)

struct fnc {
    int (*fnc)(int *nums, int numsSize, int target);
    const char *tag;
    double elap;
};

int capacity = 0;
int *buf = NULL;
jmp_buf jbuf;

int opt_d;                              // 1=dump array on faults
int opt_i;                              // 1=ignore errors

int
orig(int *nums, int numsSize, int target)
{
    int m = 0;
    int l = 0;
    int r = numsSize - 1;

    do {
        m = r - (r - l) / 2;
        if (nums[m] < target)
            r = m + 1;
        else
            l = m - 1;
    } while ((l <= r) && (nums[m] != target));

    return m;
}

int
flat(int *nums, int numsSize, int target)
{
    int m = 0;
    int r = -1;

    for (;  m < numsSize;  ++m) {
        if (nums[m] == target) {
            r = m;
            break;
        }
    }

    return r;
}

int
fix1(int *nums, int numsSize, int target)
{
    int m;
    int l = 0;
    int v;
    int h = numsSize - 1;
    int ret = -1;

    while (l <= h) {
        m = l + (h - l) / 2;

        v = nums[m];
        if (v == target) {
            ret = m;
            break;
        }

        if (v < target)
            l = m + 1;
        else
            h = m - 1;
    }

    return ret;
}

struct fnc fnclist[] = {
    { .fnc = flat, .tag = "flat" },
    { .fnc = fix1, .tag = "fix1" },
    { .fnc = orig, .tag = "orig" },
    { .fnc = NULL },
};

double tscbias = 0.0;

double
tscgetf(void)
{
    struct timespec ts;
    double sec;

    clock_gettime(CLOCK_MONOTONIC,&ts);

    sec = ts.tv_nsec;
    sec /= 1e9;
    sec += ts.tv_sec;

    return sec;
}

void
tscinit(void)
{
    double tscbeg;
    double tscend;
    double elap = 99.0;

    for (int tryno = 1;  tryno <= 100;  ++tryno) {
        tscbeg = tscgetf();
        tscend = tscgetf();
        tscend -= tscbeg;
        if (tscend < elap)
            elap = tscend;
    }

    printf("tscinit: %.9f\n",elap);
    tscbias = elap;
}

double
tscelap(double tscbeg,double tscend)
{

    tscend -= tscbeg;
    tscend -= tscbias;

    return tscend;
}

int
xrand(int mod)
{
    int val = rand();
    val %= mod;
    return val;
}

int
dofnc(struct fnc *fnc,int *buf,int count,int idxexp,int valexp)
{
    double tscbeg = 0.0;
    double tscend;
    double elap = 99.0;
    int tmout;
    int fault = 0;

    int idxact = -1;

    for (int tryno = 1;  tryno <= 3;  ++tryno) {
        tmout = sigsetjmp(jbuf,1);

        // timeout occurred -- get [phony] elapsed time
        if (tmout) {
            tscend = tscgetf();
            elap = tscelap(tscbeg,tscend);
            break;
        }

        alarm(1);

        tscbeg = tscgetf();
        idxact = fnc->fnc(buf,count,valexp);
        tscend = tscgetf();

        alarm(0);

        // remember the best time
        tscend = tscelap(tscbeg,tscend);
        if (tscend < elap)
            elap = tscend;
    }

    // check result
    do {
        if (idxact == idxexp)
            break;
        if (tmout)
            break;
        fault = 1;
    } while (0);

    printf("%.9f %s I:%d/%d V:%d%s%s\n",
        elap,fnc->tag,idxexp,idxact,valexp,
        tmout ? " (TIME)" : "",
        fault ? " (FAULT)" : "");

    return fault;
}

void
dotest(int count)
{
    int fault = 0;

    if (count <= 0)
        count = xrand(10000) + 1;

    if (count > capacity) {
        capacity = count;
        buf = realloc(buf,sizeof(buf) * capacity);
    }

    int val = 0;
    for (int idx = 0;  idx < count;  ++idx) {
        int dta = xrand(99) + 1;
        val += dta;
        buf[idx] = val;
    }

    int idxexp = xrand(count);

    printf("\n");
    printf("dotest: count=%d lo=%d hi=%d\n",count,buf[0],buf[count - 1]);

    for (struct fnc *fnc = fnclist;  fnc->fnc != NULL;  ++fnc) {
        int valexp = buf[idxexp];
        if (dofnc(fnc,buf,count,idxexp,valexp))
            fault = 1;

        // check for value lower than min
        valexp = buf[0] - 1;
        if (dofnc(fnc,buf,count,-1,valexp))
            fault = 1;

        // check for value higher than max
        valexp = buf[count - 1] + 1;
        if (dofnc(fnc,buf,count,-1,valexp))
            fault = 1;
    }

    // dump array on error/fault
    do {
        if (! fault)
            break;

        if (! opt_d)
            break;

        int totlen = 0;

        printf("ARRAY:\n");
        for (int idx = 0;  idx < count;  ++idx) {
            totlen += printf(" %d:%d",idx,buf[idx]);
            if (totlen > 65) {
                printf("\n");
                totlen = 0;
            }
        }
        if (totlen > 0)
            printf("\n");
    } while (0);

    if (fault && (! opt_i))
        sysfault("dotest: aborting ...\n");
}

void
sighdr(int signo)
{
    siglongjmp(jbuf,1);
}

int
main(int argc,char **argv)
{

    --argc;
    ++argv;

    for (;  argc > 0;  --argc, ++argv) {
        char *cp = *argv;
        if (*cp != '-')
            break;

        cp += 2;
        switch (cp[-1]) {
        case 'i':
            opt_i = ! opt_i;
            break;
        }
    }

    setlinebuf(stdout);
    signal(SIGALRM,sighdr);

    tscinit();

    for (int tstno = 1;  tstno <= 10;  ++tstno)
        dotest(-1);

    for (int count = 1;  count <= 100;  count += 3)
        dotest(count);
}

這是程序 output：

tscinit: 0.000000026

dotest: count=9384 lo=44 hi=470252
0.000002194 flat I:2253/2253 V:114229
0.000010131 flat I:-1/-1 V:43
0.000007218 flat I:-1/-1 V:470253
0.000000081 fix1 I:2253/2253 V:114229
0.000000079 fix1 I:-1/-1 V:43
0.000000048 fix1 I:-1/-1 V:470253
1.000016339 orig I:2253/-1 V:114229 (TIME)
1.000014557 orig I:-1/-1 V:43 (TIME)
1.000009347 orig I:-1/-1 V:470253 (TIME)

dotest: count=5993 lo=55 hi=299486
0.000001431 flat I:1324/1324 V:67045
0.000006461 flat I:-1/-1 V:54
0.000006460 flat I:-1/-1 V:299487
0.000000035 fix1 I:1324/1324 V:67045
0.000000038 fix1 I:-1/-1 V:54
0.000000053 fix1 I:-1/-1 V:299487
1.000009870 orig I:1324/-1 V:67045 (TIME)
1.000029920 orig I:-1/-1 V:54 (TIME)
1.000009728 orig I:-1/-1 V:299487 (TIME)

dotest: count=8955 lo=17 hi=445765
0.000000465 flat I:426/426 V:21179
0.000006463 flat I:-1/-1 V:16
0.000008701 flat I:-1/-1 V:445766
0.000000063 fix1 I:426/426 V:21179
0.000000064 fix1 I:-1/-1 V:16
0.000000048 fix1 I:-1/-1 V:445766
1.000016202 orig I:426/-1 V:21179 (TIME)
1.000009818 orig I:-1/-1 V:16 (TIME)
1.000009810 orig I:-1/-1 V:445766 (TIME)

dotest: count=340 lo=70 hi=16804
0.000000014 flat I:7/7 V:486
0.000000372 flat I:-1/-1 V:69
0.000000372 flat I:-1/-1 V:16805
0.000000035 fix1 I:7/7 V:486
0.000000017 fix1 I:-1/-1 V:69
0.000000028 fix1 I:-1/-1 V:16805
1.000009743 orig I:7/-1 V:486 (TIME)
1.000009810 orig I:-1/-1 V:69 (TIME)
1.000032772 orig I:-1/-1 V:16805 (TIME)

dotest: count=1964 lo=18 hi=97889
0.000001410 flat I:1298/1298 V:64382
0.000001936 flat I:-1/-1 V:17
0.000002120 flat I:-1/-1 V:97890
0.000000041 fix1 I:1298/1298 V:64382
0.000000035 fix1 I:-1/-1 V:17
0.000000039 fix1 I:-1/-1 V:97890
1.000009294 orig I:1298/-1 V:64382 (TIME)
1.000013307 orig I:-1/-1 V:17 (TIME)
1.000008924 orig I:-1/-1 V:97890 (TIME)

dotest: count=21 lo=50 hi=1126
0.000000031 flat I:17/17 V:1024
0.000000029 flat I:-1/-1 V:49
0.000000030 flat I:-1/-1 V:1127
0.000000022 fix1 I:17/17 V:1024
0.000000021 fix1 I:-1/-1 V:49
0.000000016 fix1 I:-1/-1 V:1127
1.000023933 orig I:17/-1 V:1024 (TIME)
1.000008840 orig I:-1/-1 V:49 (TIME)
1.000009542 orig I:-1/-1 V:1127 (TIME)

dotest: count=4228 lo=96 hi=214509
0.000004465 flat I:4139/4139 V:210346
0.000004559 flat I:-1/-1 V:95
0.000004559 flat I:-1/-1 V:214510
0.000000038 fix1 I:4139/4139 V:210346
0.000000039 fix1 I:-1/-1 V:95
0.000000039 fix1 I:-1/-1 V:214510
1.000009090 orig I:4139/-1 V:210346 (TIME)
1.000009507 orig I:-1/-1 V:95 (TIME)
1.000009268 orig I:-1/-1 V:214510 (TIME)

dotest: count=7858 lo=70 hi=390374
0.000002593 flat I:2398/2398 V:120399
0.000005670 flat I:-1/-1 V:69
0.000005670 flat I:-1/-1 V:390375
0.000000033 fix1 I:2398/2398 V:120399
0.000000044 fix1 I:-1/-1 V:69
0.000000060 fix1 I:-1/-1 V:390375
1.000009538 orig I:2398/-1 V:120399 (TIME)
1.000009622 orig I:-1/-1 V:69 (TIME)
1.000011139 orig I:-1/-1 V:390375 (TIME)

dotest: count=8963 lo=60 hi=446543
0.000000585 flat I:537/537 V:26242
0.000006468 flat I:-1/-1 V:59
0.000006462 flat I:-1/-1 V:446544
0.000000069 fix1 I:537/537 V:26242
0.000000045 fix1 I:-1/-1 V:59
0.000000059 fix1 I:-1/-1 V:446544
1.000011390 orig I:537/-1 V:26242 (TIME)
1.000009583 orig I:-1/-1 V:59 (TIME)
1.000009641 orig I:-1/-1 V:446544 (TIME)

dotest: count=6304 lo=60 hi=317397
0.000000607 flat I:556/556 V:27198
0.000004554 flat I:-1/-1 V:59
0.000004549 flat I:-1/-1 V:317398
0.000000064 fix1 I:556/556 V:27198
0.000000048 fix1 I:-1/-1 V:59
0.000000054 fix1 I:-1/-1 V:317398
1.000044305 orig I:556/-1 V:27198 (TIME)
1.000018003 orig I:-1/-1 V:59 (TIME)
1.000013375 orig I:-1/-1 V:317398 (TIME)

dotest: count=1 lo=34 hi=34
0.000000011 flat I:0/0 V:34
0.000000011 flat I:-1/-1 V:33
0.000000011 flat I:-1/-1 V:35
0.000000009 fix1 I:0/0 V:34
0.000000011 fix1 I:-1/-1 V:33
0.000000018 fix1 I:-1/-1 V:35
0.000000017 orig I:0/0 V:34
1.000009685 orig I:-1/-1 V:33 (TIME)
1.000009896 orig I:-1/-1 V:35 (TIME)

dotest: count=4 lo=99 hi=250
0.000000009 flat I:0/0 V:99
0.000000013 flat I:-1/-1 V:98
0.000000013 flat I:-1/-1 V:251
0.000000012 fix1 I:0/0 V:99
0.000000012 fix1 I:-1/-1 V:98
0.000000015 fix1 I:-1/-1 V:251
1.000016379 orig I:0/-1 V:99 (TIME)
1.000009174 orig I:-1/-1 V:98 (TIME)
1.000009049 orig I:-1/-1 V:251 (TIME)

dotest: count=7 lo=33 hi=324
0.000000014 flat I:1/1 V:69
0.000000016 flat I:-1/-1 V:32
0.000000015 flat I:-1/-1 V:325
0.000000013 fix1 I:1/1 V:69
0.000000013 fix1 I:-1/-1 V:32
0.000000013 fix1 I:-1/-1 V:325
1.000013937 orig I:1/-1 V:69 (TIME)
1.000011886 orig I:-1/-1 V:32 (TIME)
1.000015891 orig I:-1/-1 V:325 (TIME)

dotest: count=10 lo=51 hi=446
0.000000013 flat I:3/3 V:213
0.000000023 flat I:-1/-1 V:50
0.000000016 flat I:-1/-1 V:447
0.000000014 fix1 I:3/3 V:213
0.000000014 fix1 I:-1/-1 V:50
0.000000016 fix1 I:-1/-1 V:447
1.000009785 orig I:3/-1 V:213 (TIME)
1.000009554 orig I:-1/-1 V:50 (TIME)
1.000009879 orig I:-1/-1 V:447 (TIME)

dotest: count=13 lo=13 hi=724
0.000000014 flat I:2/2 V:141
0.000000025 flat I:-1/-1 V:12
0.000000017 flat I:-1/-1 V:725
0.000000012 fix1 I:2/2 V:141
0.000000013 fix1 I:-1/-1 V:12
0.000000014 fix1 I:-1/-1 V:725
1.000010021 orig I:2/-1 V:141 (TIME)
1.000009654 orig I:-1/-1 V:12 (TIME)
1.000014118 orig I:-1/-1 V:725 (TIME)

dotest: count=16 lo=76 hi=645
0.000000022 flat I:13/13 V:573
0.000000027 flat I:-1/-1 V:75
0.000000021 flat I:-1/-1 V:646
0.000000020 fix1 I:13/13 V:573
0.000000014 fix1 I:-1/-1 V:75
0.000000016 fix1 I:-1/-1 V:646
1.000015331 orig I:13/-1 V:573 (TIME)
1.000013445 orig I:-1/-1 V:75 (TIME)
1.000009196 orig I:-1/-1 V:646 (TIME)

dotest: count=19 lo=54 hi=970
0.000000026 flat I:10/10 V:565
0.000000029 flat I:-1/-1 V:53
0.000000029 flat I:-1/-1 V:971
0.000000014 fix1 I:10/10 V:565
0.000000014 fix1 I:-1/-1 V:53
0.000000016 fix1 I:-1/-1 V:971
1.000009642 orig I:10/-1 V:565 (TIME)
1.000009610 orig I:-1/-1 V:53 (TIME)
1.000009402 orig I:-1/-1 V:971 (TIME)

dotest: count=22 lo=48 hi=1076
0.000000017 flat I:7/7 V:444
0.000000029 flat I:-1/-1 V:47
0.000000025 flat I:-1/-1 V:1077
0.000000020 fix1 I:7/7 V:444
0.000000014 fix1 I:-1/-1 V:47
0.000000022 fix1 I:-1/-1 V:1077
1.000010220 orig I:7/-1 V:444 (TIME)
1.000014361 orig I:-1/-1 V:47 (TIME)
1.000013648 orig I:-1/-1 V:1077 (TIME)

dotest: count=25 lo=42 hi=1184
0.000000031 flat I:16/16 V:785
0.000000032 flat I:-1/-1 V:41
0.000000024 flat I:-1/-1 V:1185
0.000000021 fix1 I:16/16 V:785
0.000000014 fix1 I:-1/-1 V:41
0.000000015 fix1 I:-1/-1 V:1185
1.000009388 orig I:16/-1 V:785 (TIME)
1.000009349 orig I:-1/-1 V:41 (TIME)
1.000011995 orig I:-1/-1 V:1185 (TIME)

dotest: count=28 lo=26 hi=1497
0.000000024 flat I:8/8 V:450
0.000000033 flat I:-1/-1 V:25
0.000000033 flat I:-1/-1 V:1498
0.000000022 fix1 I:8/8 V:450
0.000000014 fix1 I:-1/-1 V:25
0.000000016 fix1 I:-1/-1 V:1498
1.000010067 orig I:8/-1 V:450 (TIME)
1.000009827 orig I:-1/-1 V:25 (TIME)
1.000014836 orig I:-1/-1 V:1498 (TIME)

dotest: count=31 lo=24 hi=1436
0.000000047 flat I:20/20 V:915
0.000000069 flat I:-1/-1 V:23
0.000000075 flat I:-1/-1 V:1437
0.000000070 fix1 I:20/20 V:915
0.000000031 fix1 I:-1/-1 V:23
0.000000030 fix1 I:-1/-1 V:1437
1.000013925 orig I:20/-1 V:915 (TIME)
1.000010255 orig I:-1/-1 V:23 (TIME)
1.000011782 orig I:-1/-1 V:1437 (TIME)

dotest: count=34 lo=87 hi=1745
0.000000029 flat I:16/16 V:980
0.000000038 flat I:-1/-1 V:86
0.000000036 flat I:-1/-1 V:1746
0.000000010 fix1 I:16/16 V:980
0.000000015 fix1 I:-1/-1 V:86
0.000000018 fix1 I:-1/-1 V:1746
1.000015356 orig I:16/-1 V:980 (TIME)
1.000013789 orig I:-1/-1 V:86 (TIME)
1.000009397 orig I:-1/-1 V:1746 (TIME)

dotest: count=37 lo=11 hi=1650
0.000000038 flat I:29/29 V:1331
0.000000039 flat I:-1/-1 V:10
0.000000038 flat I:-1/-1 V:1651
0.000000014 fix1 I:29/29 V:1331
0.000000022 fix1 I:-1/-1 V:10
0.000000023 fix1 I:-1/-1 V:1651
1.000010122 orig I:29/-1 V:1331 (TIME)
1.000013891 orig I:-1/-1 V:10 (TIME)
1.000016981 orig I:-1/-1 V:1651 (TIME)

dotest: count=40 lo=89 hi=2263
0.000000036 flat I:23/23 V:1575
0.000000040 flat I:-1/-1 V:88
0.000000040 flat I:-1/-1 V:2264
0.000000023 fix1 I:23/23 V:1575
0.000000014 fix1 I:-1/-1 V:88
0.000000016 fix1 I:-1/-1 V:2264
1.000009746 orig I:23/-1 V:1575 (TIME)
1.000013715 orig I:-1/-1 V:88 (TIME)
1.000012347 orig I:-1/-1 V:2264 (TIME)

dotest: count=43 lo=23 hi=2179
0.000000035 flat I:26/26 V:1503
0.000000049 flat I:-1/-1 V:22
0.000000042 flat I:-1/-1 V:2180
0.000000020 fix1 I:26/26 V:1503
0.000000021 fix1 I:-1/-1 V:22
0.000000017 fix1 I:-1/-1 V:2180
1.000012506 orig I:26/-1 V:1503 (TIME)
1.000012921 orig I:-1/-1 V:22 (TIME)
1.000009616 orig I:-1/-1 V:2180 (TIME)

dotest: count=46 lo=66 hi=2278
0.000000019 flat I:1/1 V:84
0.000000043 flat I:-1/-1 V:65
0.000000043 flat I:-1/-1 V:2279
0.000000014 fix1 I:1/1 V:84
0.000000015 fix1 I:-1/-1 V:65
0.000000022 fix1 I:-1/-1 V:2279
1.000012092 orig I:1/-1 V:84 (TIME)
1.000009936 orig I:-1/-1 V:65 (TIME)
1.000009509 orig I:-1/-1 V:2279 (TIME)

dotest: count=49 lo=29 hi=2565
0.000000036 flat I:26/26 V:1662
0.000000046 flat I:-1/-1 V:28
0.000000044 flat I:-1/-1 V:2566
0.000000022 fix1 I:26/26 V:1662
0.000000015 fix1 I:-1/-1 V:28
0.000000017 fix1 I:-1/-1 V:2566
1.000009716 orig I:26/-1 V:1662 (TIME)
1.000009498 orig I:-1/-1 V:28 (TIME)
1.000009616 orig I:-1/-1 V:2566 (TIME)

dotest: count=52 lo=72 hi=2728
0.000000040 flat I:28/28 V:1354
0.000000048 flat I:-1/-1 V:71
0.000000054 flat I:-1/-1 V:2729
0.000000014 fix1 I:28/28 V:1354
0.000000014 fix1 I:-1/-1 V:71
0.000000023 fix1 I:-1/-1 V:2729
1.000010207 orig I:28/-1 V:1354 (TIME)
1.000011530 orig I:-1/-1 V:71 (TIME)
1.000009826 orig I:-1/-1 V:2729 (TIME)

dotest: count=55 lo=54 hi=2677
0.000000031 flat I:17/17 V:993
0.000000055 flat I:-1/-1 V:53
0.000000049 flat I:-1/-1 V:2678
0.000000041 fix1 I:17/17 V:993
0.000000014 fix1 I:-1/-1 V:53
0.000000022 fix1 I:-1/-1 V:2678
1.000009676 orig I:17/-1 V:993 (TIME)
1.000009553 orig I:-1/-1 V:53 (TIME)
1.000009855 orig I:-1/-1 V:2678 (TIME)

dotest: count=58 lo=6 hi=2569
0.000000048 flat I:31/31 V:1507
0.000000057 flat I:-1/-1 V:5
0.000000056 flat I:-1/-1 V:2570
0.000000015 fix1 I:31/31 V:1507
0.000000021 fix1 I:-1/-1 V:5
0.000000022 fix1 I:-1/-1 V:2570
1.000009519 orig I:31/-1 V:1507 (TIME)
1.000010096 orig I:-1/-1 V:5 (TIME)
1.000013881 orig I:-1/-1 V:2570 (TIME)

dotest: count=61 lo=55 hi=3223
0.000000063 flat I:54/54 V:2935
0.000000052 flat I:-1/-1 V:54
0.000000052 flat I:-1/-1 V:3224
0.000000033 fix1 I:54/54 V:2935
0.000000022 fix1 I:-1/-1 V:54
0.000000016 fix1 I:-1/-1 V:3224
1.000018225 orig I:54/-1 V:2935 (TIME)
1.000011663 orig I:-1/-1 V:54 (TIME)
1.000011810 orig I:-1/-1 V:3224 (TIME)

dotest: count=64 lo=24 hi=3309
0.000000056 flat I:42/42 V:2305
0.000000060 flat I:-1/-1 V:23
0.000000060 flat I:-1/-1 V:3310
0.000000015 fix1 I:42/42 V:2305
0.000000034 fix1 I:-1/-1 V:23
0.000000023 fix1 I:-1/-1 V:3310
1.000009987 orig I:42/-1 V:2305 (TIME)
1.000009362 orig I:-1/-1 V:23 (TIME)
1.000009670 orig I:-1/-1 V:3310 (TIME)

dotest: count=67 lo=22 hi=3548
0.000000030 flat I:21/21 V:1149
0.000000076 flat I:-1/-1 V:21
0.000000076 flat I:-1/-1 V:3549
0.000000041 fix1 I:21/21 V:1149
0.000000016 fix1 I:-1/-1 V:21
0.000000018 fix1 I:-1/-1 V:3549
1.000009903 orig I:21/-1 V:1149 (TIME)
1.000014023 orig I:-1/-1 V:21 (TIME)
1.000009173 orig I:-1/-1 V:3549 (TIME)

dotest: count=70 lo=43 hi=3672
0.000000014 flat I:1/1 V:80
0.000000094 flat I:-1/-1 V:42
0.000000079 flat I:-1/-1 V:3673
0.000000021 fix1 I:1/1 V:80
0.000000017 fix1 I:-1/-1 V:42
0.000000024 fix1 I:-1/-1 V:3673
1.000009550 orig I:1/-1 V:80 (TIME)
1.000009619 orig I:-1/-1 V:42 (TIME)
1.000009878 orig I:-1/-1 V:3673 (TIME)

dotest: count=73 lo=96 hi=3334
0.000000046 flat I:38/38 V:1790
0.000000081 flat I:-1/-1 V:95
0.000000081 flat I:-1/-1 V:3335
0.000000022 fix1 I:38/38 V:1790
0.000000023 fix1 I:-1/-1 V:95
0.000000024 fix1 I:-1/-1 V:3335
1.000009914 orig I:38/-1 V:1790 (TIME)
1.000009592 orig I:-1/-1 V:95 (TIME)
1.000012527 orig I:-1/-1 V:3335 (TIME)

dotest: count=76 lo=29 hi=3658
0.000000077 flat I:67/67 V:3384
0.000000084 flat I:-1/-1 V:28
0.000000090 flat I:-1/-1 V:3659
0.000000033 fix1 I:67/67 V:3384
0.000000016 fix1 I:-1/-1 V:28
0.000000024 fix1 I:-1/-1 V:3659
1.000013745 orig I:67/-1 V:3384 (TIME)
1.000009361 orig I:-1/-1 V:28 (TIME)
1.000115935 orig I:-1/-1 V:3659 (TIME)

dotest: count=79 lo=80 hi=3719
0.000000074 flat I:64/64 V:3195
0.000000087 flat I:-1/-1 V:79
0.000000093 flat I:-1/-1 V:3720
0.000000015 fix1 I:64/64 V:3195
0.000000016 fix1 I:-1/-1 V:79
0.000000024 fix1 I:-1/-1 V:3720
1.000015493 orig I:64/-1 V:3195 (TIME)
1.000012758 orig I:-1/-1 V:79 (TIME)
1.000011825 orig I:-1/-1 V:3720 (TIME)

dotest: count=82 lo=65 hi=4759
0.000000062 flat I:54/54 V:3385
0.000000095 flat I:-1/-1 V:64
0.000000094 flat I:-1/-1 V:4760
0.000000018 fix1 I:54/54 V:3385
0.000000016 fix1 I:-1/-1 V:64
0.000000017 fix1 I:-1/-1 V:4760
1.000010221 orig I:54/-1 V:3385 (TIME)
1.000013208 orig I:-1/-1 V:64 (TIME)
1.000012146 orig I:-1/-1 V:4760 (TIME)

dotest: count=85 lo=37 hi=4072
0.000000037 flat I:24/24 V:1160
0.000000098 flat I:-1/-1 V:36
0.000000097 flat I:-1/-1 V:4073
0.000000023 fix1 I:24/24 V:1160
0.000000023 fix1 I:-1/-1 V:36
0.000000024 fix1 I:-1/-1 V:4073
1.000009917 orig I:24/-1 V:1160 (TIME)
1.000010126 orig I:-1/-1 V:36 (TIME)
1.000009681 orig I:-1/-1 V:4073 (TIME)

dotest: count=88 lo=80 hi=4413
0.000000033 flat I:22/22 V:1009
0.000000100 flat I:-1/-1 V:79
0.000000100 flat I:-1/-1 V:4414
0.000000015 fix1 I:22/22 V:1009
0.000000017 fix1 I:-1/-1 V:79
0.000000024 fix1 I:-1/-1 V:4414
1.000009871 orig I:22/-1 V:1009 (TIME)
1.000009935 orig I:-1/-1 V:79 (TIME)
1.000014026 orig I:-1/-1 V:4414 (TIME)

dotest: count=91 lo=32 hi=4993
0.000000098 flat I:88/88 V:4857
0.000000103 flat I:-1/-1 V:31
0.000000102 flat I:-1/-1 V:4994
0.000000016 fix1 I:88/88 V:4857
0.000000017 fix1 I:-1/-1 V:31
0.000000018 fix1 I:-1/-1 V:4994
1.000012311 orig I:88/-1 V:4857 (TIME)
1.000011487 orig I:-1/-1 V:31 (TIME)
1.000011817 orig I:-1/-1 V:4994 (TIME)

dotest: count=94 lo=40 hi=4409
0.000000081 flat I:73/73 V:3272
0.000000105 flat I:-1/-1 V:39
0.000000111 flat I:-1/-1 V:4410
0.000000022 fix1 I:73/73 V:3272
0.000000023 fix1 I:-1/-1 V:39
0.000000023 fix1 I:-1/-1 V:4410
1.000009915 orig I:73/-1 V:3272 (TIME)
1.000009373 orig I:-1/-1 V:39 (TIME)
1.000009815 orig I:-1/-1 V:4410 (TIME)

dotest: count=97 lo=46 hi=4978
0.000000070 flat I:62/62 V:3483
0.000000108 flat I:-1/-1 V:45
0.000000107 flat I:-1/-1 V:4979
0.000000016 fix1 I:62/62 V:3483
0.000000016 fix1 I:-1/-1 V:45
0.000000018 fix1 I:-1/-1 V:4979
1.000013970 orig I:62/-1 V:3483 (TIME)
1.000012102 orig I:-1/-1 V:45 (TIME)
1.000013793 orig I:-1/-1 V:4979 (TIME)

dotest: count=100 lo=83 hi=4704
0.000000109 flat I:99/99 V:4704
0.000000117 flat I:-1/-1 V:82
0.000000111 flat I:-1/-1 V:4705
0.000000023 fix1 I:99/99 V:4704
0.000000016 fix1 I:-1/-1 V:82
0.000000024 fix1 I:-1/-1 V:4705
1.000009811 orig I:99/-1 V:4704 (TIME)
1.000009868 orig I:-1/-1 V:82 (TIME)
1.000009902 orig I:-1/-1 V:4705 (TIME)

為什么我花在二分搜索上的時間比線性搜索多？

問題描述

1 個解決方案

解決方案1
5 已采納 2023-02-01 19:32:36

為什么我花在二分搜索上的時間比線性搜索多？

問題描述

1 個解決方案

解決方案1 5 已采納 2023-02-01 19:32:36

解決方案1
5 已采納 2023-02-01 19:32:36