Rat_in_a_Maze_Backtracking_2

#include <stdio.h> 
  
// Maze size 
#define N 4 
  
bool solveMazeUtil( 
    int maze[N][N], int x, 
    int y, int sol[N][N]); 
  
/* A utility function to print  
solution matrix sol[N][N] */
void printSolution(int sol[N][N]) 
{ 
    for (int i = 0; i < N; i++) { 
        for (int j = 0; j < N; j++) 
            printf(" %d ", sol[i][j]); 
        printf("\n"); 
    } 
} 
  
/* A utility function to check if x,  
y is valid index for N*N maze */
bool isSafe(int maze[N][N], int x, int y) 
{ 
    // if (x, y outside maze) return false 
    if ( 
        x >= 0 && x < N && y >= 0 
        && y < N && maze[x][y] == 1) 
        return true; 
  
    return false; 
} 
  
/* This function solves the Maze problem  
using Backtracking. It mainly uses  
solveMazeUtil() to solve the problem.  
It returns false if no path is possible,  
otherwise return true and prints the path  
in the form of 1s. Please note that there  
may be more than one solutions, this  
function prints one of the feasible  
solutions.*/
bool solveMaze(int maze[N][N]) 
{ 
    int sol[N][N] = { { 0, 0, 0, 0 }, 
                      { 0, 0, 0, 0 }, 
                      { 0, 0, 0, 0 }, 
                      { 0, 0, 0, 0 } }; 
  
    if (solveMazeUtil( 
            maze, 0, 0, sol) 
        == false) { 
        printf("Solution doesn't exist"); 
        return false; 
    } 
  
    printSolution(sol); 
    return true; 
} 
  
/* A recursive utility function  
to solve Maze problem */
bool solveMazeUtil( 
    int maze[N][N], int x, 
    int y, int sol[N][N]) 
{ 
    // if (x, y is goal) return true 
    if ( 
        x == N - 1 && y == N - 1 
        && maze[x][y] == 1) { 
        sol[x][y] = 1; 
        return true; 
    } 
  
    // Check if maze[x][y] is valid 
    if (isSafe(maze, x, y) == true) { 
        // mark x, y as part of solution path 
        sol[x][y] = 1; 
  
        /* Move forward in x direction */
        if (solveMazeUtil( 
                maze, x + 1, y, sol) 
            == true) 
            return true; 
  
        /* If moving in x direction 
           doesn't give solution then  
           Move down in y direction  */
        if (solveMazeUtil( 
                maze, x, y + 1, sol) 
            == true) 
            return true; 
  
        /* If none of the above movements  
           work then BACKTRACK: unmark  
           x, y as part of solution path */
        sol[x][y] = 0; 
        return false; 
    } 
  
    return false; 
} 
  
// driver program to test above function 
int main() 
{ 
    int maze[N][N] = { { 1, 0, 0, 0 }, 
                       { 1, 1, 0, 1 }, 
                       { 0, 1, 0, 0 }, 
                       { 1, 1, 1, 1 } }; 
  
    solveMaze(maze); 
    return 0; 
}