Problem #158
Best Hacker in the World
Foxtrot and Vampire decided to play a game to decide who is a better hacker. They have n tiles in a line out of which m are white rest all are black. Their task is to change all the black tiles with white by following a simple procedure. They can change a black tile with white only if there is atleast one white tile adjacent to that black tile. Now they have n=74 and m=13 and the 13 positions (indexed 1) of white tiles are 6,14,19,20,21,24,30,43,58,61,69,70,73
They want to find the total number of ways in which it can be done. Help Vampire find the answer as he cannot come out in daytime.
Report your answer modulo 10^9+7.