Find All Groups of Farmland

LeetCode - 1992. Find All Groups of Farmland
Approach

• WE FIRST CREATE A FARMER FUNCTION THAT WE WILL CALL RECURSIVELY
• IT WILL CHECK IF THE LAND WE ARE TRYING TO ACCESS IS OUT OF BOUNDS OR IS NOT A FIELD IN WHICH CASE IT WILL JUST RETURN BACK
• ONCE WE HAVE A FIELD THAT IS IN BOUNDS AND NOT ZERO
• WE MARK IT ZERO TO KNOW THAT WE HAVE ALREADY VISITED THIS POINT AND NEED NOT CONSIDER IT AGAIN
• NOW IN OUR ARRAY CONTAINING THE LEFT MOST POINTS AND RIGHT MOST POINTS
• INITIALLY THE POINT IN LAND THAT WE FIRST ENCOUNTER A FIELD LEFT MOST AND RIGHT MOST POINTS ARE ITSELF ONLY
• NOW IN THE RECURSIVE FUNCTION WE COMPARE OUR FIELD COORDINATED TO THE MIN AND MAX OF THE ORIGINAL COORDINATES AND MODIFY THEM ACCORDINGLY
• LEFT MOST POINT WILL BE THE LEAST POSSIBLE COORDINATE
• RIGHT MOST POINT WILL BE THE MAX POSSIBLE COORDINTE
• JUST RETURN THE OUTPUT ARRAY

/**
 * @param {number[][]} land
 * @return {number[][]}
 */
var findFarmland = function (land) {
    let rows = land.length;
    let cols = land[0].length;
    let endRow = 0;
    let endCol = 0;
    let result = [];

    callDFS = (i, j) => {
        if (i < 0 || j < 0 || i >= rows || j >= cols || land[i][j] == 0) {
            return;
        }
        endRow = Math.max(endRow, i);
        endCol = Math.max(endCol, j);

        land[i][j] = 0;
        callDFS(i + 1, j);
        callDFS(i - 1, j);
        callDFS(i, j + 1);
        callDFS(i, j - 1);

    }

    for (let i = 0; i < rows; i++) {
        for (let j = 0; j < cols; j++) {
            if (land[i][j] === 1) {
                endRow = 0;
                endCol = 0;
                // call recursion
                callDFS(i, j);
                result.push([i, j, endRow, endCol]);
            }
        }
    }

    return result;

};

console.log(findFarmland([[1, 0, 0], [0, 1, 1], [0, 1, 1]]))