Question 2 - Finding the shortest path

const grid = [
  ['S', '1', '0', '1', '1'],
  ['1', '1', '0', '1', '1'],
  ['0', '1', '1', '1', '0'],
  ['1', '0', '0', '1', 'E']
];

// output: 7

 
function bfsRecursive(grid, startX, startY, distance = 0, visited = new Set()){  
    visited.add(`${startX} ${startY}`);  
    const map = [  
        [-1,0], //top  
        [1,0], //bottom  
        [0,-1], //left  
        [0,1], //right  
    ]  
  
    if(grid[startX][startY] === 'E'){  
  
        return distance;  
    }  
    let result = Infinity;  
    for(const [dx, dy] of map){  
        const newX = startX+dx;  
        const newY = startY+dy;  
  
        if(  
            newX >= 0  
            && newX < grid.length  
            && newY >= 0  
            && newY < grid[newX].length  
            && grid[newX][newY] !== '0'  
            && !visited.has(`${newX} ${newY}`)  
        ){  
  
            const number = bfsRecursive(grid, newX, newY, distance+1, visited);  
            if(number !== -1 && number < result){  
                result = number;  
            }  
        }  
  
    }  
  
    return result;  
}  

 
function solution(grid){  
    let startX, startY;  
  
    for(let x=0; x < grid.length; x++){  
        for(let y=0; y < grid[x].length; y++){  
            if(grid[x][y] === 'S'){  
                startX=x;  
                startY=y;  
                break;            }  
        }  
    }  
    // const result = bfsQueue(grid, startX, startY);  
    const result = bfsRecursive(grid,startX, startY);  
  
}  
const grid = [  
    ['S', '1', '0', '1', '1'],  
    ['1', '1', '0', '1', '1'],  
    ['0', '1', '1', '1', '0'],  
    ['1', '0', '0', '1', 'E']  
];  
  
solution(grid);

function bfsQueue(grid, startX, startY){  
    const directions = [  
        [-1, 0], //top  
        [1, 0], //bottom  
        [0, -1], //left  
        [0, 1] //right  
    ]  
    const queue = [[startX, startY, 0]];  
    const visited = new Set();  
    visited.add(`${startX} ${startY}`);  
    while(queue.length > 0) {  
        const [x, y, distance] = queue.shift();  
        console.log("=>(2.js:14) x,y,distance", x,y,distance);  
        if(grid[x][y] === 'E'){  
            return distance;  
        }  
        for(const [dx, dy] of directions){  
            const newX = x + dx;  
            const newY = y + dy;  
            if(  
                newX >= 0  
                && newX < grid.length  
                && newY >= 0  
                && newY < grid[newX].length  
                && grid[newX][newY] !== '0'  
                && !visited.has(`${newX} ${newY}`)  
            ){  
                queue.push([newX, newY, distance + 1])  
                visited.add(`${newX} ${newY}`)  
            }        }  
  
    }  
  
    return -1;  
}  
 
function solution(grid){  
    let startX, startY;  
  
    for(let x=0; x < grid.length; x++){  
        for(let y=0; y < grid[x].length; y++){  
            if(grid[x][y] === 'S'){  
                startX=x;  
                startY=y;  
                break;            }  
        }  
    }  
    const result = bfsQueue(grid, startX, startY);  
     
  
}  
const grid = [  
    ['S', '1', '0', '1', '1'],  
    ['1', '1', '0', '1', '1'],  
    ['0', '1', '1', '1', '0'],  
    ['1', '0', '0', '1', 'E']  
];  
  
solution(grid);