#include<bits/stdc++.h>//头文件 using namespace std;//命名空间 //定义 int sum_nm(int n,int m){ int sum= 0; for (int i = n;i<= m;i++){ sum+=i; } return sum; } int main(){ // 1 10 10 20 30 40 cout<<sum_nm(1,10)<<" "; cout<<sum_nm(20,30)<<" "; cout<<sum_nm(35,45)<<" "; return 0; }