Hello !

I have been trying to solve a problem but I am not able to solve it.

Problem Statement : Find the number of strings of length “N” made up of only 3 characters – a, b, c such that “a” occurs at least “min_a” times and at most “max_a” times, “b” occurs at least “min_b” times and at most “max_b” times and “c” occurs at least “min_c” times and at most “max_c” times. Note that all permutations of same string count as 1, so “abc” is same as “bac”.

Constraints

1<=T<=1000 1<=N<=10^9 1<=min_a<= max_a<=10^9 1<=min_b<= max_b<=10^9 1<=min_c<= max_c<=10^9

Problem Link on spoj : LINK

Please provide some hints !

Thanks !