Codeforce A. DZY Loves Chessboard

1. #include< bits/stdc++.h >
2. using namespace std;
3. int main(){
4. int n, m, b = 0, w = 0;
5. cin >> n >> m;
6. char data[n][m];
7. for(int i = 0; i < n; i++) {
8. for(int j = 0; j < m; j++) {
9. cin >> data[i][j];
10. }
11. }
12. for(int i = 0; i < n; i++) {
13. for(int j = 0; j < m; j++) {
14. if(data[i][j] == '.') {
15. if((i+j) % 2) cout << 'W';
16. else cout << 'B';
17. }else cout << data[i][j];
18. }
19. cout << endl;
20. }
21. return 0;
22. }

Codeforce A. Yaroslav and Permutations

1. #include< iostream >
2. using namespace std;
3. int main() {
4. int n, x;
5. cin >> n;
6. int ar[10001] = {0};
7. for(int i = 0; i < n; i++) {
8. cin >> x;
9. ar[x]++;
10. if(ar[x] > (n+1)/2) return cout << "NO\n", 0;
11. }
12. cout << "YES\n";
13. return 0;
14. }

Codeforce A. Collecting Beats is Fun

1. #include< bits/stdc++.h >
2. using namespace std;
3. int main(){
4. int k;
5. char a;
6. cin >> k;
7. int ar[10] = {0};
8. for(int i = 0; i < 16; i++){
9. cin >> a;
10. ar[a]++;
11. }
12. for(int i = 1; i < 10; i++)
13. if(ar[i+'0'] > 2*k) return cout << "NO\n", 0;
14. cout << "YES\n";
15. return 0;
16. }

Codeforce A. Levko and Table

1. #include< iostream >
2. using namespace std;
3. int main()
4. {
5. int n, k;
6. cin >> n >> k;
7. for(int i = 0; i < n; i++) {
8. for(int j = 0; j < n; j++) {
9. cout << ((i == j)? k : 0 ) << " ";
10. }
11. cout << endl;
12. }
13. return 0;
14. }