[英]how to replace the most common character in a string with the second most common in the string in c?
I wrote a C function that receives a string from the user, and replaces the letter with the highest frequency, with the letter with the second highest frequency in the string.我写了一个 C function 从用户那里接收一个字符串,并将频率最高的字母替换为字符串中频率第二高的字母。 Example: For the input i love you more
, the string i levo yeu mero
will be returned示例:对于输入i love you more
,将返回字符串i levo yeu mero
#include <stdio.h>
#include <string.h>
void stringReplace(char str1[]);
int main()
{
char str1[100] = { 0 };
stringReplace(str1);
return 0;
}
void stringReplace(char str1[])
{
char ch1, ch2;
int i, h, j, p, n, len, counter1 = 0, counter2 = 0, first, second, times;
printf("Please enter the string - maximum = 100 characters:\n");
printf("User input: ");
fgets(str1, 100, stdin);
str1[strcspn(str1, "\n")] = 0;
len = strlen(str1);
for (i = 0; i < len; i++) {
counter1 = 0;
for (j = 0; j < len; j++) {
if (str1[i] == str1[j]) {
counter1++;
}
if (counter1 > counter2) {
first = i;
}
}
counter2 = counter1;
} //character which shows up most - found.
counter2 = 0;
for (p = 0; p < len; p++) {
for (n = 0; n < len; n++) {
if (str1[p] == str1[n]) {
counter1++;
}
if (counter1 < first && counter1 > counter2) {
second = p;
}
}
counter2 = counter1;
}
ch1 = str1[first];
ch2 = str1[second];
for (h = 0; h < len; h++) {
if (str1[h] == ch1) {
str1[h] = ch2;
}
}
puts(str1);
}
This is the code I have done, and instead of changing the string it prints the same thing.这是我所做的代码,而不是更改字符串它打印相同的东西。 for example:例如:
Please enter the string - maximum = 100 characters:
User input: i love you more
i love you more
Suggest: divide and conquer with helper functions.建议:用辅助函数分而治之。
Think about the sub-problem: Counting the 1st & 2nd most popular.想想子问题:计算第 1 和第 2 最受欢迎。
Walk the string.走绳子。 At each character count its occurrence with the rest of the string.在每个字符处,使用字符串的 rest 计算其出现次数。 O(n*n) O(n*n)
When a better than 2nd place count is detected, adjust 1st and 2nd place.当检测到优于第 2 位的计数时,调整第 1 位和第 2 位。
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
void most_popular2(const char *s, char pop[2]) {
pop[0] = pop[1] = 0;
size_t pop_count[2] = {0, 0};
while (*s) {
// Do not count white-space.
if (!isspace(*(const unsigned char* )s)) {
// How popular is *s?
size_t count = 1;
// sum all the matches on the rest of the string
for (const char *r = s + 1; *r; r++) {
if (*s == *r) {
count++;
}
}
// Test if better than the 2nd most popular.
if (count > pop_count[1] && *s != pop[0]) {
if (count > pop_count[0]) {
// Demote 1st place to 2nd place.
pop_count[1] = pop_count[0];
pop[1] = pop[0];
// Save new 1st place.
pop_count[0] = count;
pop[0] = *s;
} else {
// Save new 2nd place.
pop_count[1] = count;
pop[1] = *s;
}
}
}
s++;
}
}
Sample样本
int main() {
char s[] = "i love you more i love you more\n";
char pop[2];
most_popular2(s, pop);
printf("1st:%c 2nd:%c\n", pop[0], pop[1]);
}
Output Output
1st:o 2nd:e
Leave it to OP to take the 2 most popular characters and form the desired output.让 OP 选择 2 个最受欢迎的字符并形成所需的 output。
More efficient code could copy the string, sort it O(n*(lng(n)) and then walk it to find the 2 most popular.更高效的代码可以复制字符串,对它进行 O(n*(lng(n)) 排序,然后遍历它以找到最流行的 2 个。
thanks for the help, now i got it.谢谢你的帮助,现在我明白了。 this is what i did:这就是我所做的:
#include <stdio.h>
#include<stdio.h>
#include<string.h>
#define ASCII_A 97 // ascii for A is 97
#define MAXSIZE 50 // max size for string
#define ALPHABETS 26 //total number of alphabets
void stringReplace(char s[], int a[]);
int main()
{
char s[MAXSIZE] = {0};
int a[ALPHABETS] = {0}
stringReplace(s);
return 0;
}
/*
function to replace the most common charcter with the second one
input: the string
output: none
*/
void stringReplace(char s[], int a[])
{
int i;
int count = 0;
int max = 0, max2 = 0;
int index, index2;
printf("Enter the string:\n");
fgets(s, MAXSIZE, stdin);
s[strcspn(s, "\n")] = 0;
for(i=0; i<26; i++) // initialize all array elements to zero
{
a[i]=0;
}
for(i=0; i<strlen(s); i++) // loop for traversing the string
{
a[s[i]-ASCII_A]++; // increment by 1 for each occurrence.
}
for(i=0; i< ALPHABETS; i++) //prints alphabets and occurrence.
{
count = a[i];
if (count > max)
{
max = count;
index = i;
}
if(count < max && count > 1)
{
max2 = count;
index2 = i;
}
}
printf("%c\n", ASCII_A+index);
printf("%c\n", ASCII_A+index2);
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.