Solution2.ts

/**
 Do not return anything, modify matrix in-place instead.
 */
function setZeroes(matrix: number[][]): void {
    const m = matrix.length;
    const n = matrix[0].length;
    let l0 = false;
    let r0 = false;
    for (let i = 0; i < m; i++) {
        if (matrix[i][0] === 0) {
            l0 = true;
            break;
        }
    }
    for (let j = 0; j < n; j++) {
        if (matrix[0][j] === 0) {
            r0 = true;
            break;
        }
    }
    for (let i = 0; i < m; i++) {
        for (let j = 0; j < n; j++) {
            if (matrix[i][j] === 0) {
                matrix[i][0] = 0;
                matrix[0][j] = 0;
            }
        }
    }
    for (let i = 1; i < m; i++) {
        for (let j = 1; j < n; j++) {
            if (matrix[i][0] === 0 || matrix[0][j] === 0) {
                matrix[i][j] = 0;
            }
        }
    }
    if (l0) {
        for (let i = 0; i < m; i++) {
            matrix[i][0] = 0;
        }
    }
    if (r0) {
        for (let j = 0; j < n; j++) {
            matrix[0][j] = 0;
        }
    }
}