Merge pull request #88 from vaithak/master

Nice idea! Thanks for contribution!

Backtracking/Rat_maze.cpp

@@ -0,0 +1,74 @@
+/*
+	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;
+}