[Leetcode]74. Search a 2D Matrix

Write an efficient algorithm that searches for a value in an m x n 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.

For example,

Consider the following matrix:

[  [1,   3,  5,  7],  [10, 11, 16, 20],  [23, 30, 34, 50]]

Given target = 3, return true.

class Solution {public:    bool searchMatrix(vector<vector<int>>& matrix, int target) {        int row = 0;        int col = matrix[0].size() - 1;        while (row < matrix.size() && col > -1) {            if (matrix[row][col] == target) {                return true;            }            else if (matrix[row][col] < target) {                row++;            }            else                col--;        }        return false;    }};