Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
Example 1:
Input: matrix = [ [1, 3, 5, 7], [10, 11, 16, 20], [23, 30, 34, 50] ] target = 3 Output: true
Example 2:
Input: matrix = [ [1, 3, 5, 7], [10, 11, 16, 20], [23, 30, 34, 50] ] target = 13 Output: false
my code:
class Solution {
public:
bool searchMatrix(vector<vector<int>>& matrix, int target) {
int row = matrix.size();
if (row == 0) return false;
int col = matrix[0].size();
if (col == 0) return false;
int flag = 0;
for (int i = 0; i < row; ++i) {
if (matrix[i][col-1] >= target) {
flag = i;
break;
}
}
int l = 0, r = col;
while (l < r) {
int m = (l + r) / 2;
if (matrix[flag][m] == target) return true;
if (matrix[flag][m] > target) {
r = m;
}
if (matrix[flag][m] < target) {
l = m+1;
}
}
return false;
}
};
原文：https://www.cnblogs.com/ruruozhenhao/p/9839405.html