Calculate S(n)
 
Time Limit: 10000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
 Total Submission(s): 9401 Accepted Submission(s): 3415 
Problem Description
 
  Calculate S(n). 
 
 S(n)=1 
 3+2 
 3 +3 
 3 +......+n 
 3 . 
 
 
Input
 
Each line will contain one integer N(1 < n < 1000000000). Process to end of file.
 
 
Output
 
For each case, output the last four dights of S(N) in one line.
 
 
Sample Input
 
1 2
 
 
Sample Output
 
0001
0009
  
  
  
  
   
   //S(n)=1^3+2^3+3^3+......+n^3可转化为S(n)=(1+2+3+......+n)^2;
  
  
知道这个转化就简单了。
  
  
#include<stdio.h>
#include<string.h>
#include<algorithm>
#define ll long long
using namespace std;
int main()
{
	ll n;
	while(scanf("%lld",&n)!=EOF)
	{
		ll sum=((n*(n+1)/2%10000)*(n*(n+1)/2%10000))%10000;
		printf("%04lld\n",sum);
	}
	return 0;
}   
   
  
  









