write code in c++

Consider the King Nohintzen Problem, where an angry king desires to place as many fla can in a given area divided into NxN regions. For this given area divided into 55 grid, only one flag can be placed in each cell, and the to simply place flags in as many cells as you can give the following condition: No two flags can ever be placed into the same diagonal i.e. no clash of flags diagonally Propose a backtracking algorithm/program to the given problem and report the maximum number of flags you could place using this algorithm