Revise paste Sudoku [Brute force]

#include <stdio.h>

int main(){
	int n, corr = 0;
	scanf("%d", &n);
	for(int tc=1; tc<=n; tc++){
		int board[9][9];
		bool correct = true;
		for(int i=0; i<9 ;i++)
			for(int j=0; j<9; j++)
				scanf("%d", &board[i][j]);
		for(int i=0; i<9 && correct;i++){
			bool flag[10] = {0};
			for(int j=0; j<9; j++){
				if(flag[board[i][j]]){
					correct = false;
					break;
				}else{
					flag[board[i][j]] = true;
				}
			}
		}
		for(int i=0; i<9 && correct;i++){
			bool flag[10] = {0};
			for(int j=0; j<9; j++){
				if(flag[board[j][i]]){
					correct = false;
					break;
				}else{
					flag[board[j][i]] = true;
				}
			}
		}		
		for(int i=0; i<9; i+=3){
			for(int j=0; j<9; j+=3){
				bool flag[10] = {0};
				for(int k=i; k<i+3; k++){
					for(int l=j; l<j+3; l++){
						if(flag[board[k][l]]){
							correct = false;
							break;
						}else{
							flag[board[k][l]] = true;
						}
					}
				}
			}
		}
		if(correct){
			corr++;
			printf("Case #%d: TRUE\n", tc);
		}else{
			printf("Case #%d: FALSE\n", tc);
		}
	}
	printf("%.2f%%\n", (double)corr*100/n);
	return 0;
}