9X9 Sudoku Solver in C (#256)

Add 9X9 Sudoku Solver in C

Author: manavmittal05

9X9_Sudoku_Solver/sudoku_solver.c

@@ -0,0 +1,60 @@
+#include <stdio.h>
+
+int solve();
+
+char sudoku[9][9];
+int isPossible(int i, int j, char k);
+
+int main(){
+
+    for(int i = 0; i < 9; i++){
+        for(int j = 0; j < 9; j++){
+            scanf("%c ", &sudoku[i][j]);
+        }
+    }
+    solve();
+    for(int i = 0; i < 9; i++){
+        for(int j = 0; j < 9; j++){
+            printf("%c ", sudoku[i][j]);
+        }
+        printf("\n");
+    }
+}
+
+int isPossible(int i, int j, char k){
+    for(int x = 0; x < 9; x++){
+        if(sudoku[x][j] == k || sudoku[i][x] == k){
+            return 0;
+        }
+    }
+    for(int x = i - (i%3); x < i - (i%3) + 3; x++){
+        for(int y = j - (j%3); y < j - (j%3) + 3; y++){
+            if(sudoku[x][y] == k){
+                return 0;
+            }
+        }
+    }
+    return 1;
+}
+
+int solve(){
+    for(int i = 0; i < 9; i++){
+        for(int j = 0; j < 9; j++){
+            if(sudoku[i][j] == '.'){
+                for(char k = '1'; k <= '9'; k++){
+                    if(isPossible(i, j, k) == 1){
+                        sudoku[i][j] = k;
+                        if(solve() == 1){
+                            return 1;
+                        }
+                        else{
+                            sudoku[i][j] = '.';
+                        }
+                    }
+                }
+                return 0;
+            }
+        }
+    }
+    return 1;
+}