题解

#include <iostream>
#include <algorithm>
using namespace std;

int vis[15];
int arr[5][5];
int ans[5][5];
bool flag = true;

bool check(){
int sum = arr[1][1] + arr[1][2] + arr[1][3];
for (int i=1; i<=3; i++){
int temp = 0;
for (int j=1; j<=3; j++){
temp += arr[i][j];
}
if (temp != sum) return false;
}
for (int i=1; i<=3; i++){
int temp = 0;
for (int j=1; j<=3; j++){
temp += arr[j][i];
}
if (temp != sum) return false;
}
return true;
}

void copy(){
for (int i=1; i<=3; i++){
for (int j=1; j<=3; j++){
ans[i][j] = arr[i][j];
}
}
return ;
}

void dfs(int x, int y){
if (y == 4){
x += 1;
y = 1;
}

if (x == 4){
    if (check()) {
        if (flag){
            flag = false;
            copy();
        } else{
            cout << "Too Many" << endl;
            exit(0);
        }
    }
    return ;
} 
if (arr[x][y] != 0) {
    dfs(x, y+1);
    return ;
}

for (int i=1; i<=9; i++){
    if (vis[i]) continue;
    vis[i] = 1;
    arr[x][y] = i;
    dfs(x, y+1);
    arr[x][y] = 0;
    vis[i] = 0;
}
return ;

}

int main(){
for (int i=1; i<=3; i++){
for (int j=1; j<=3; j++){
cin >> arr[i][j];
vis[arr[i][j]] = 1;
}
}
dfs(1, 1);
if (!flag){
for (int i=1; i<=3; i++){
for (int j=1; j<=3; j++){
cout << ans[i][j] << " ";
}
cout << endl;
}
} else cout << "Too Many";
return 0;
}