memory.cpp: In function 'void play()':
memory.cpp:5:20: error: 'pair' was not declared in this scope
5 | map <char, pair<int, int>>m;
| ^~~~
memory.cpp:5:9: error: 'map' was not declared in this scope
5 | map <char, pair<int, int>>m;
| ^~~
memory.cpp:5:14: error: expected primary-expression before 'char'
5 | map <char, pair<int, int>>m;
| ^~~~
memory.cpp:8:21: error: 'm' was not declared in this scope
8 | if (m[c].first == 0) {
| ^
memory.cpp:15:23: error: 'm' was not declared in this scope
15 | for (auto x : m) {
| ^