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41 | public class Solution {
public boolean searchMatrix(int[][] matrix, int target) {
if (matrix == null || matrix.length == 0) return false;
int place = binarySearchColumn(matrix, target);
if (place != matrix.length && matrix[place][0] == target) return true;
if (place == 0) return false;
int location = binarySearchRow(matrix[place-1], target);
return location != matrix[place-1].length && matrix[place-1][location] == target;
}
private int binarySearchRow(int row[], int target){
int left = 0;
int right = row.length-1;
while (left <= right){
int mid = (left+right)/2;
if (row[mid] > target){
right = mid-1;
}else if (row[mid] < target){
left = mid+1;
}else{
return mid;
}
}
return left;
}
private int binarySearchColumn(int matrix[][], int target){
int left = 0;
int right = matrix.length-1;
while (left <= right){
int mid = (left+right)/2;
if (matrix[mid][0] > target){
right = mid-1;
}else if (matrix[mid][0] < target){
left = mid+1;
}else{
return mid;
}
}
return left;
}
}
|
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