摘要：#include<stdio.h> int main() { int n=100,r1,r2,r3,r4; r1=n*(n+1)/2; r2=(n+1)*n/2; r3=n/2*(n+1); r4=(n+1)/2*n; printf("n=%d\n",n); printf("r1=%d\n",r1) 阅读全文