三种循环实现等差数列求和

for循环

#include<stdio.h>int Sum(int num)
{int result = 0;for (int i = 1; i <= num; ++i){result += i;}return result;
}

while循环

#include<stdio.h>int Sum_while(int num)
{int result = 0;int i = 1;while (i <= num){result += i;i++;}return result;
}

do while循环

#include<stdio.h>int Sum_dowhile(int num)
{int result = 0;int i = 0;do{result += i;i++;} while (i <= num);return result;
}