请大佬帮看，while和for的区别

MrKeanu @ 2020-02-17 11:40:19

#include<stdio.h>

int main(){
    int n,k;
    double s=0.0;

    scanf("%d",&k);
    for(n=1;s<=k;n++){
        s =s+ 1.0/n;    
    printf("%d",n);

    return 0;
} 

#include<stdio.h>

int main(){
    int n,k;
    double s=0.0;

    scanf("%d",&k);
    while(s<=k){
        n++;
        s+=1.0/n;
    }
    printf("%d",n);

    return 0;
} 

by iTwinkle @ 2020-02-17 11:41:53

好迷的for循环语句

by bunH2O @ 2020-02-17 11:42:25

for先加再判断，while直接判断

by iTwinkle @ 2020-02-17 11:42:27

你的n赋初值了吗

by UnyieldingTrilobite @ 2020-02-17 11:42:57

for先更新s再n++ while先n++再更新s

by UnyieldingTrilobite @ 2020-02-17 11:43:17

还有n没初始化

by cmll02 @ 2020-02-17 11:43:38

当 s<=k 时， n=n+1，再执行一次，此时 s>k，但仍然会再执行 n++，然后判断，跳出。

by iTwinkle @ 2020-02-17 11:43:54

for和while的执行顺序不一样，for是先执行再n+1，while语句里是n+1再执行

by pocafup @ 2020-02-17 11:44:04

for要定义次数

by iTwinkle @ 2020-02-17 11:44:55

@pocafup 不一定要规定次数，只要有终止条件就行了

by UnyieldingTrilobite @ 2020-02-17 11:45:01

while和for干嘛这么写不香吗

While the value of s is less than the value of k or the value of s equals the value of k do{
    Let the value of n be the value of n plus 1;
    Let the value of s be the value of s plus 1.0 divided by n;
}