From a87400a51acefbecf78767d90387335973d0448d Mon Sep 17 00:00:00 2001
From: Saikat Nayek <88332980+Saikat2407@users.noreply.github.com>
Date: Tue, 4 Oct 2022 20:30:26 +0530
Subject: [PATCH 1/2] Pushed problem from Leetcode
Suduku solver
---
Algorithms/Medium/SudokuSolver.java | 81 +++++++++++++++++++++++++++++
1 file changed, 81 insertions(+)
create mode 100644 Algorithms/Medium/SudokuSolver.java
diff --git a/Algorithms/Medium/SudokuSolver.java b/Algorithms/Medium/SudokuSolver.java
new file mode 100644
index 0000000..bb4580f
--- /dev/null
+++ b/Algorithms/Medium/SudokuSolver.java
@@ -0,0 +1,81 @@
+// https://leetcode.com/problems/sudoku-solver/
+// Agniva
+public class SudokuSolver {
+ public static void main(String[] args) {
+ int[][] board = new int[][]{
+ {3, 0, 6, 5, 0, 8, 4, 0, 0},
+ {5, 2, 0, 0, 0, 0, 0, 0, 0},
+ {0, 8, 7, 0, 0, 0, 0, 3, 1},
+ {0, 0, 3, 0, 1, 0, 0, 8, 0},
+ {9, 0, 0, 8, 6, 3, 0, 0, 5},
+ {0, 5, 0, 0, 9, 0, 6, 0, 0},
+ {1, 3, 0, 0, 0, 0, 2, 5, 0},
+ {0, 0, 0, 0, 0, 0, 0, 7, 4},
+ {0, 0, 5, 2, 0, 6, 3, 0, 0}
+ };
+
+ solve(board, 0,0);
+ }
+
+ public static void solve(int[][] board, int row, int col){
+ if(row == board.length){
+ display(board);
+ return;
+ }
+ int nRow = 0;
+ int nCol = 0;
+ if(col == board[0].length-1){
+ nRow = row + 1;
+ nCol = 0;
+ }else{
+ nRow = row;
+ nCol = col + 1;
+ }
+
+ if(board[row][col] != 0){
+ solve(board, nRow, nCol);
+ }else {
+ for (int po = 1; po <= 9; po++) {
+ if(isValid(board, row, col, po)){
+ board[row][col] = po;
+ solve(board, nRow, nCol);
+ board[row][col] = 0;
+ }
+ }
+ }
+
+ }
+
+ public static boolean isValid(int[][] board, int row, int col, int num){
+ for (int i = 0; i < board[0].length; i++) {
+ if(board[row][i] == num){
+ return false;
+ }
+ }
+ for (int i = 0; i < board.length; i++) {
+ if(board[i][col] == num){
+ return false;
+ }
+ }
+ int rowStart = row/3 * 3;
+ int colStart = col/3 * 3;
+
+ for (int i = 0; i < 3; i++) {
+ for (int j = 0; j < 3; j++) {
+ if(board[rowStart+i][colStart+j] == num){
+ return false;
+ }
+ }
+ }
+ return true;
+ }
+
+ public static void display(int[][] board){
+ for (int i = 0; i < board.length; i++) {
+ for (int j = 0; j < board[0].length; j++) {
+ System.out.print(board[i][j] + " ");
+ }
+ System.out.println();
+ }
+ }
+}
From d52afbed5980e1005052c34700629f1c1d7d318d Mon Sep 17 00:00:00 2001
From: Saikat Nayek <88332980+Saikat2407@users.noreply.github.com>
Date: Tue, 4 Oct 2022 20:53:08 +0530
Subject: [PATCH 2/2] Pushed Find Kth Bit problem
---
Algorithms/Medium/FindKthBit.java | 35 +++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
create mode 100644 Algorithms/Medium/FindKthBit.java
diff --git a/Algorithms/Medium/FindKthBit.java b/Algorithms/Medium/FindKthBit.java
new file mode 100644
index 0000000..d5064dd
--- /dev/null
+++ b/Algorithms/Medium/FindKthBit.java
@@ -0,0 +1,35 @@
+// https://leetcode.com/problems/find-kth-bit-in-nth-binary-string/
+public class KthBit {
+ public static void main(String[] args) {
+ System.out.println(findKthBit(4, 11));
+ }
+ public static char findKthBit(int n, int k) {
+ if(k==1){
+ return '0';
+ }
+
+ return findNthString("0", n).charAt(k-1);
+ }
+ public static String findNthString(String s, int n){
+ if(n==0){
+ return s;
+ }
+ s = s + "1" + reverseInverse(s);
+
+ return findNthString(s, n-1);
+ }
+
+ public static String reverseInverse(String s){
+ StringBuilder sb = new StringBuilder();
+ for (int i = 0; i < s.length(); i++) {
+ if (s.charAt(i) == '0') {
+ sb.append('1');
+ }
+ else{
+ sb.append('0');
+ }
+ }
+
+ return sb.reverse().toString();
+ }
+}
\ No newline at end of file