HDU 1001 Sum Problem 水题

Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 440436    Accepted Submission(s): 110576

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

 

Recommend

We have carefully selected several similar problems for you:   1002  1003  1004  1092  1089 

水题 打表就可以过

#include <stdio.h>

long long a[1000000]={0};
int main()
{
	long long i,j,n;
	
	for(i=1;i<1000000;i++)
	{
		a[i]=i+a[i-1];
	}
	while(~scanf("%I64d",&n))
	{
		printf("%I64d\n\n",a[n]);
	}
	
	return 0;
}