rename Backtracking -> backtracking (#654)

backtracking/rat_maze.cpp

@@ -0,0 +1,73 @@
+/*
+	A Maze is given as N*N binary matrix of blocks where source block is the upper
+	left most block i.e., maze[0][0] and destination block is lower rightmost 
+	block i.e., maze[N-1][N-1]. A rat starts from source and has to reach destination.
+	The rat can move only in two directions: forward and down. In the maze matrix, 
+	0 means the block is dead end and 1 means the block can be used in the path 
+	from source to destination.
+*/
+#include <iostream>
+#define size 4
+
+using namespace std;
+
+int solveMaze(int currposrow, int currposcol, int maze[size][size], int soln[size][size])
+{
+	if ((currposrow == size - 1) && (currposcol == size - 1))
+	{
+		soln[currposrow][currposcol] = 1;
+		for (int i = 0; i < size; ++i)
+		{
+			for (int j = 0; j < size; ++j)
+			{
+				cout << soln[i][j];
+			}
+			cout << endl;
+		}
+		return 1;
+	}
+	else
+	{
+		soln[currposrow][currposcol] = 1;
+
+		// if there exist a solution by moving one step ahead in a collumn
+		if ((currposcol < size - 1) && maze[currposrow][currposcol + 1] == 1 && solveMaze(currposrow, currposcol + 1, maze, soln))
+		{
+			return 1;
+		}
+
+		// if there exists a solution by moving one step ahead in a row
+		if ((currposrow < size - 1) && maze[currposrow + 1][currposcol] == 1 && solveMaze(currposrow + 1, currposcol, maze, soln))
+		{
+			return 1;
+		}
+
+		// the backtracking part
+		soln[currposrow][currposcol] = 0;
+		return 0;
+	}
+}
+
+int main(int argc, char const *argv[])
+{
+	int maze[size][size] = {
+		{1, 0, 1, 0},
+		{1, 0, 1, 1},
+		{1, 0, 0, 1},
+		{1, 1, 1, 1}};
+
+	int soln[size][size];
+
+	for (int i = 0; i < size; ++i)
+	{
+		for (int j = 0; j < size; ++j)
+		{
+			soln[i][j] = 0;
+		}
+	}
+
+	int currposrow = 0;
+	int currposcol = 0;
+	solveMaze(currposrow, currposcol, maze, soln);
+	return 0;
+}