Time Limit:3000MS Memory Limit:32768KB 64bit IO Format:%I64d & %I64u
Description
When Teddy was a child , he was always thinking about some simple math problems ,such as “What it’s 1 cup of water plus 1 pile of dough ..” , “100 yuan buy 100 pig” .etc..

One day Teddy met a old man in his dream , in that dream the man whose name was“RuLai” gave Teddy a problem :
Given an N , can you calculate how many ways to write N as i * j + i + j (0 < i <= j) ?
Teddy found the answer when N was less than 10…but if N get bigger , he found it was too difficult for him to solve.
Well , you clever ACMers ,could you help little Teddy to solve this problem and let him have a good dream ?
One day Teddy met a old man in his dream , in that dream the man whose name was“RuLai” gave Teddy a problem :
Given an N , can you calculate how many ways to write N as i * j + i + j (0 < i <= j) ?
Teddy found the answer when N was less than 10…but if N get bigger , he found it was too difficult for him to solve.
Well , you clever ACMers ,could you help little Teddy to solve this problem and let him have a good dream ?
Input
The first line contain a T(T <= 2000) . followed by T lines ,each line contain an integer N (0<=N <= 1010).
Output
For each case, output the number of ways in one line.
Sample Input
2 1 3
Sample Output
0 1
题意:给一个N,求有多少个0<i<=j,满足i*j+i+j=N?
分析:求i*j+i+j=N 就是求 (i+1)*(j+1)=N+1 的个数,所以求N+1的所有小于等于sqrt(N+1)的因数(不含1)个数即可
#include<stdio.h>
#include<math.h>
#define ll long long
int main()
{
ll N;
int t,ans=0;
scanf("%d",&t);
while(t--)
{
ans=0;
scanf("%I64d",&N);
N++;
ll m=(int)sqrt(N)+1;
for(int i=2;i<m;i++)if(N%i==0)ans++;
printf("%d\n",ans);
}
}