i. Valid_Sudoku.cpp

/*
Problem Link: https://practice.geeksforgeeks.org/problems/is-sudoku-valid4820/1/
Title: Is Sudoku Valid
Difficulty: Medium
Author: Hariket Sukesh Kumar Sheth
Language: C++
*/

#include <bits/stdc++.h>
using namespace std;

class Solution{
public:
    int isValid(vector<vector<int>> mat)
    {
        bool row[10][10] = {false}, col[10][10] = {false}, grid[10][10] = {false};
        
        for(int i = 0; i < 9; i++)
        {
            for(int j = 0; j < 9; j++)
            {
                int num = mat[i][j];
                if(num == 0)
                continue;
                int grid_idx = (i/3) * 3 + (j/3);
                
                if(row[i][num] || col[j][num] || grid[grid_idx][num])
                return 0;
                row[i][num] = col[j][num] = grid[grid_idx][num] = true;
            }
        }
        return 1;
    }
};


int main(){
    int t;
    cin>>t;
    while(t--){
        vector<vector<int>> mat(9, vector<int>(9, 0));
        for(int i = 0;i < 81;i++)
            cin>>mat[i/9][i%9];
        
        Solution ob;
        cout<<ob.isValid(mat)<<"\n";
    }
    return 0;
}