HDOJ2058

/*等差数列求和公式*/

#include <iostream> 

#include <cstring>
#include <string>
#include <cstdio>
#include <algorithm>
#include <stack>
#include <math.h>
#include<iostream>

using namespace std;

int main()
{
long long int m, n;
while (cin >> m >> n,m||n)
{
for (int i = sqrt(2*n); i > 0; i--) // 当和是m时 实际最多的位数（由等差数列求和公式推)
{
long long int a = n / i - (i - 1) / 2;
if((2*a+i-1)*i==2*n)  cout << "[" << a << "," << a + i - 1 << "]" << endl;
}
cout << endl;
}
return 0;
}