implements sqrt using a basic binary search strategy

an iterative implementation @param coins @param amount @return

Key idea: keep doubling divisor till no larger than dividend, then subtract amplified divisor from dividend till dividend is small than original divis

computes the longest increasing path starting from a given locatioin (i, j) @param matrix extended matrix @param longest LIP value matrix @param dirs

checks if placing Q at [row][col] is safe @param board 2D board char array @param N size of board @param row current row working on @param col curren

solves the N-Queen problem by moving forward column by column if safe and moving backward if not @param board 2D board char array @param N size of bo

a recursive implementation @param coins @param amount @return

The following code solves the problem of detecting the staring node of a cycle in a linked list if there is one. The key idea is to use a slow and a f