Search a 2D Matrix

Description

Write an efficient algorithm that searches for a value target in an m x n integer matrix matrix. This matrix has the following properties:

• Integers in each row are sorted from left to right.
• The first integer of each row is greater than the last integer of the previous row.

 

Example 1:

Input: matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,60]], target = 3
Output: true

Example 2:

Input: matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,60]], target = 13
Output: false

 

Constraints:

• m == matrix.length
• n == matrix[i].length
• 1 <= m, n <= 100
• -104 <= matrix[i][j], target <= 104

Solution(javascript)

/**
 * @param {number[][]} matrix
 * @param {number} target
 * @return {boolean}
 */
var searchMatrix = function(matrix, target) {
    // for(let i = 0; i < matrix.length; i++){
    //     for(let j = 0; j < matrix[i].length; j++){
    //         if(matrix[i][j] == target) {
    //             return true;
    //         }
    //     }
    // }
    // return false;
    const n = matrix.length;

    for (let i = 0; i < n; i++) {
        if (matrix[i].indexOf(target) !== -1) return true;
    }

    return false;
};