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SearchA2DMatrix.java
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49 lines (41 loc) · 1.12 KB
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package Java;
public class SearchA2DMatrix {
public boolean solution1(int[][] matrix, int target) {
int n = matrix.length;
if(n == 0) return false;
int m = matrix[0].length;
if(m == 0) return false;
int i = n-1;
int j = 0;
while(i >= 0 && j < m){
if(matrix[i][j] == target){
return true;
} else if(matrix[i][j] > target){
i--;
} else {
j++;
}
}
return false;
}
/* BinarySearch */
public boolean solution2(int[][] matrix, int target) {
int n = matrix.length;
if(n == 0) return false;
int m = matrix[0].length;
if(m == 0) return false;
int l = 0;
int r = (n*m) - 1;
while(l < r){
int mid = l + (r - l) / 2;
if(matrix[mid/m][mid%m] == target){
return true;
} else if (matrix[mid/m][mid%m] < target){
l = mid + 1;
} else {
r = mid;
}
}
return matrix[r/m][r%m] == target;
}
}