Implemented Searcing in Sorted Matrix

19_2D_Array/SearchinSortedMatrix.java

@@ -0,0 +1,60 @@
+public class SearchinSortedMatrix {
+ public static int binarySearch(int arr[], int key) {
+ int low = 0;
+ int high = arr.length - 1;
+ while (low <= high) {
+ int mid = low + (high - low) / 2;
+ if (arr[mid] == key) {
+ return mid;
+ } else if (arr[mid] > key) {
+ high = mid - 1;
+ } else {
+ low = mid + 1;
+ }
+ }
+ return -1;
+ }
+
+ public static String binaryMatrixSearch(int mat[][], int key) {
+ int index = 0;
+ for (int i = 0; i < mat.length; i++) {
+ index = binarySearch(mat[i], key);
+ if (index != -1) {
+ return "key found at index (" + i + "," + index + ")";
+ }
+ }
+
+ return "Key not found";
+
+ // Time Complexity:O(nlogn)
+
+ }
+
+ public static String Optimisedsearch(int mat[][], int key) {
+ int row = 0, col = mat[0].length - 1;
+
+ while (row < mat.length && col >= 0) {
+ if (mat[row][col] == key) {
+ return "key found at index (" + row + "," + col + ")";
+ } else if (key < mat[row][col]) {
+ col--;
+ } else {
+ row++;
+ }
+
+ }
+ return "Key not found";
+ }
+
+ public static void main(String[] args) {
+ int matrix[][] = { { 1, 2, 3, 4, 5 },
+ { 6, 7, 8, 9, 10 },
+ { 11, 12, 13, 14, 15 },
+ { 16, 17, 18, 19, 20 },
+ { 21, 22, 23, 24, 25 } };
+ int key = 18;
+ System.out.println(binaryMatrixSearch(matrix, key));
+ System.out.println(Optimisedsearch(matrix, key));
+
+ }
+}