1001 Sum Problem

Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 156066    Accepted Submission(s): 36596

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

 

 

Author

DOOM III

 

今天开始做杭电的ACM，觉得挺有趣的，

刚好可以来练练编程能力。

好久没有好好编了，

写的代码看起来都觉得很傻瓜，

没办法，慢慢开始吧

#include <stdio.h>
int sum(int);

int main(){
    int input,output;
    while (scanf("%d",&input)==1)
    {
        output = sum(input);
        printf("%d\n\n",output);
    }
    return 0;
}
int sum(int n){
    int sum,i;
    sum=0;
    for (i=1;i<=n;i++)
    {
        sum+=i;
    }
    return sum;
}

 

 网络代码：

#include <stdio.h>
int main(){
    int n, sum;
    while (scanf("%d", &n) == 1){
        sum = 0;
        while (n != 0){
            sum += n--;
        }
        printf("%d\n\n", sum);
    }
    return 0;
}