Added a program that checks for a vaild sudoku

ValidSudokuCheck/ValidSudokuCheck.cpp

@@ -0,0 +1,107 @@
+//This program checks wether the sudoku entered is a valid sudoku(solvable) or not.
+#include <bits/stdc++.h>
+using namespace std;
+
+void print(vector<vector<char>> board){
+	//printing the sudoku
+	for(auto it=board.begin();it!=board.end();it++){
+		for(auto ij=(*it).begin();ij!=(*it).end();ij++){
+			printf("%c ",*ij);
+		}
+		printf("\n");	
+	}
+}
+
+bool isValidSudoku(vector<vector<char>>& board) {
+	//checking for row
+	//check for unique numbers 
+	for(auto it=board.begin();it!=board.end();it++){
+		set<char> s;
+		for(auto ij=(*it).begin();ij!=(*it).end();ij++){
+			if(*ij!='.'){
+				//finding unique numbers(represented as characters here) 
+				if(s.find(*ij)==s.end()){
+				s.insert(*ij);
+			}
+			else
+				return false;
+			}
+		}
+	}
+	//checking for column
+	//check for unique numbers
+	for(int i=0;i<9;i++){//9X9 dimension
+		set<char> s;
+		for(int j=0;j<9;j++){
+			if(board[j][i]!='.'){
+				//finding unique numbers(represented as characters here)
+				if(s.find(board[j][i])==s.end()){
+					s.insert(board[j][i]);
+				}
+				else
+					return false;
+			}
+		}
+	}
+	//checking for sub-boxes
+	//check for unique numbers
+	for(int x=0;x<9;x=x+3){
+		for(int i=0;i<9;i=i+3){
+			set<char> s;
+			for(int j=x;j<x+3;j++){
+				for(int k=i;k<i+3;k++){
+					//finding unique numbers(represented as characters here)
+					if(board[j][k]!='.'){
+						if(s.find(board[j][k])==s.end()){
+							s.insert(board[j][k]);
+						}
+						else
+							return false;
+					}
+				}
+			}
+		}
+	}
+	return true;
+}
+
+int main(){
+	cout<<"black spaces represented as '.'\n";
+	vector<vector<char>> a{
+	{'5','3','.','.','7','.','.','.','.'},
+	{'6','.','.','1','9','5','.','.','.'},
+	{'.','9','8','.','.','.','.','6','.'},
+	{'8','.','.','.','6','.','.','.','3'},
+	{'4','.','.','8','.','3','.','.','1'},
+	{'7','.','.','.','2','.','.','.','6'},
+	{'.','6','.','.','.','.','2','8','.'},
+	{'.','.','.','4','1','9','.','.','5'},
+	{'.','.','.','.','8','.','.','7','9'}};
+
+	print(a);
+
+	if(isValidSudoku(a))
+		cout<<"It's a valid one"<<endl;
+	else
+		cout<<"It's a invalid sudoku\n";
+
+	vector<vector<char>> b{
+	{'5','3','.','.','7','.','.','.','.'},
+	{'6','.','.','1','9','5','.','.','.'},
+	{'.','9','8','.','.','.','.','6','.'},
+	{'8','.','.','.','6','.','.','.','3'},
+	{'4','.','.','8','.','3','.','.','1'},
+	{'7','.','.','.','2','.','.','.','6'},
+	{'.','6','.','.','.','.','2','8','.'},
+	{'.','.','.','4','1','9','.','.','5'},
+	{'.','.','.','.','8','.','.','9','9'}};
+
+	print(b);
+
+	if(isValidSudoku(b))
+		cout<<"It's a valid one"<<endl;
+	else
+		cout<<"It's an invalid sudoku\n";
+
+	return 0;
+}