HDU1001：Sum Problem

HDU1002：Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 495961    Accepted Submission(s): 125818

Problem Description

Hey, welcome to HDOJ(Hangzhou Dianzi University Online Judge).

In this problem, your task is to calculate SUM(n) = 1 + 2 + 3 + ... + n.

 

 

Input

The input will consist of a series of integers n, one integer per line.

 

 

Output

For each case, output SUM(n) in one line, followed by a blank line. You may assume the result will be in the range of 32-bit signed integer.

 

 

Sample Input

1 100

 

 

Sample Output

1 5050

 思路：从 0 到 n 累加 ， 注意输出格式

#include <cstdio>

int main(){
    int n ; 
    int sum  ; 
    while(~scanf("%d" , &n)){
        sum = 0 ; 
        for(int i=0 ; i<=n ; i++){
            sum += i ; 
        }
        printf("%d\n\n" , sum) ; 
    }
    return 0 ; 
}