【LeetCode热题100（62/100）】搜索二维矩阵

题目地址： 链接

思路： 双重二分（横轴和纵轴）

/**
 * @param {number[][]} matrix
 * @param {number} target
 * @return {boolean}
 */
var searchMatrix = function(matrix, target) {
    let [n, m] = [matrix.length, matrix[0].length];
    
    let [l1, r1] = [0, n];
    while(l1 < r1) {
        let mid = (l1 + r1) >> 1;
        if( matrix[mid][m - 1] >= target ) r1 = mid;
        else l1 = mid + 1;
    }
    if(l1 >= n) return false;
    
    let [l2, r2] = [0, m];
    while(l2 < r2) {
        let mid = (l2 + r2) >> 1;
        console.log(l1, mid);
        if(matrix[l1][mid] >= target) r2 = mid;
        else l2 = mid + 1;
    }

    return matrix[l1][l2] == target ? true : false;
};