c语言计算1+2+……+n的累加求和 用while和for俩种方法?答:1,#include<stdio.h> int main(){ int n,i,sum=0;scanf("%d",&n);for(i=0;i<=n;i++)sum=sum+i;printf("%d",sum);return 0;} 2,#include<stdio.h> int main(){ int i=0,n,sum=0;scanf("%d",&n);while(i<=n){ sum=sum+i;i++;} printf("%d",sum);return 0;...