可以在单个循环上抓取嵌套循环吗？

Question

Here is the code:

#include <stdio.h>
int main() {
    int i, j;
    for(i = 0; i < 10; i++) {
        for (j = 0; j < i; j++){
            printf("*");
        }
        printf("\n");
    }
    return 0;
}

Can the code above be looped on a single loop something like this on bottom? (Though this didn't work for me.)

#include <stdio.h>
int main() {
    int i, j;
    for (i = 0, j = 0; i < 10, j < i; i++, j++){
        printf("*");
    }
    printf("\n");
    return 0;
}

Answer 1

Yes, it's possible, but you should look up what different operators do (and think about what your code should do, too).

for (int i = 10; i <= 100; i++) {
    if (i % 10 <= i / 10) {
        printf("*");
    }

    if (i % 10 == 0) {
        printf("\n");
    }
}

Answer 2

Not sensibly. You want to loop over each value of j for each value of i , which implies a nested loop. Your second example will increment both i and j after each iteration, which is very different.

In principle, you could loop a single variable from 0 to (at least) 45, and do some arithmetic to find the values of i and j from that; but that would be considerably harder to follow, and probably less efficient, so I won't suggest a way to do that.

Answer 3

You can use the comma operator for this kind of thing, although your condition part is incorrect.

It should be

for (i = 0, j = 0; i < 10 && /* perhaps || here*/ j < i; i++, j++){

Answer 4

You can write like this but its not readable.

#include <stdio.h>
int main() {
  int i, j;
  for(i=0, j=0; j<i? :(printf("\n"), j=0, i++, i<10); j++) {
    printf("*");
  }
  return 0;
}

Answer 5

Give it a try, it will work fine, without any extra iterations.

int count=1,tmp=1;
for (int i = 1; i <= 10; i++) 
{
    printf("*");
    if (count == i) {
        printf("\n");
        tmp++;
        count+=tmp;
    }
}

Answer 6

#include <stdio.h>
int main() {
    int i = 10, j = 0, k = 1; 
    while(j++ < i)
        (j == k && j <i) ? (printf("\n"),k+=1,j=0):printf("*");
    return 0;
}