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 in ascending from left to right.
- Integers in each column are sorted in ascending from top to bottom.
For example,
Consider the following 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] ]
Given target =
5
, return true
.
Given target =
20
, return false
.public class Solution {
public boolean searchMatrix(int[][] matrix, int target) {
if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
return false;
}
int row = matrix.length;
int column = matrix[0].length;
int i = 0;
int j = column - 1;
while (i >= 0 && i < row && j >= 0 && j < column) {
int val = matrix[i][j];
if (target == val) {
return true;
} else if (target > val) {
i++;
} else {
j--;
}
}
return false;
}
}
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