SIMEQN - A simple equation
Given N,A,B,C, find how many solutions exist to the equation : a + b + c <= N, such that 0 <= a <= A, 0 <= b <= B, 0 <= c <= C.
The first line contains the number of test cases T. Each test case contains 4 integers, N,A,B,C. 0 <= N,A,B,C <= 2500
Output T lines, one for each test case.
Sample Input :
4 3 2 1
1 1 1 1
Sample Output :
Haha, I wrote a solution for a+b+c==N because I didn't read carefully enough. a+b+c<=N is an inequality, not an equation.