![https://leetcode.com/problems/search-a-2d-matrix-ii/]
Write an efficient algorithm that searches for a target value in an m x n integer matrix. The matrix has the following properties:
- Integers in each row are sorted in ascending from left to right.
- Integers in each column are sorted in ascending from top to bottom.
Example 1:
Input: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 5
Output: true
Example 2:
Input: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 20
Output: false
Constraints:
- m == matrix.length
- n == matrix[i].length
- 1 <= n, m <= 300
- -109 <= matix[i][j] <= 109
- All the integers in each row are sorted in ascending order.
- All the integers in each column are sorted in ascending order.
- -109 <= target <= 109
class Solution {
public boolean searchMatrix(int[][] matrix, int target) {
int n = matrix.length;
int m = matrix[0].length;
int i = 0;
int j = m - 1;
while (i < n && j >= 0 ) {
if (target < matrix[i][j]) {
j--;
} else if (target > matrix[i][j]) {
i++;
} else {
return true;
}
}
return false;
}
}