HDU-2566 Statistics Coin

Description

Suppose a pile of n coins consisting of 1 point, 2 points, and 5 points has a total face value of m points, and find out how many possible combinations there are (the number of coins of a certain face value can be 0).

Input

The first line of the input data has a positive integer T, indicating that there are T sets of test data; the
next T line, each line has two numbers n, m, n and m have the same meaning as above.

Output

For each set of test data, please output the number of possible combinations;
each set of output occupies one line.

Sample Input

2
3 5
4 8

Sample Output

1
2

#include <iostream>

using namespace std;

int main()
{
    int n, m;
    int t;
    int top, bottom;
    cin >> t;
    while (t--){
        cin >> n >> m;
        if (m>5*n || m<n)
            cout << "0" << endl;
        else{
            top = n * 5;
            bottom = 0;
            if ((m-n)/4<top)
                top = (m-n) / 4;
            if ((m-n*2) >= 3)
                bottom = (m-n*2+2) / 3;
            cout << top-bottom+1 << endl;
        }
    }
    return 0;
}