Problem Description
Given a sequence 1,2,3,......N, your job is to calculate all the possible sub-sequences that the sum of the sub-sequence is M.
Input
Input contains multiple test cases. each case contains two integers N, M( 1 <= N, M <= 1000000000).input ends with N = M = 0.
Output
For each test case, print all the possible sub-sequence that its sum is M.The format is show in the sample below.print a blank line after each test case.
Sample Input
20 10
50 30
0 0
Sample Output
[1,4]
[10,10]
[4,8]
[6,9]
[9,11]
[30,30]
#include <string.h>
#include <stdio.h>
#include <math.h>
int main()
{
int i,j,n,m,t;
while(scanf("%d%d",&n,&m), m && n)
{
m*=2;
for(i=(int)sqrt((double)m);i>=2;i--)
{
if(m%i==0)
{
t=m/i+1-i;
if (t>=2 && t%2==0)
{
t>>=1;
if(t+i-1<=n)
printf("[%d,%d]\n",t,t+i-1);
}
}
}
m>>=1;
if(n>=m) printf("[%d,%d]\n",m,m);
printf("\n");
}
return 0;
}