View Compilation Error

0_0_37811116_22501.cpp:21:1: error: 'map' does not name a type
 map <int, int> mp;
 ^
0_0_37811116_22501.cpp: In function 'void solve()':
0_0_37811116_22501.cpp:25:5: error: 'mp' was not declared in this scope
     mp.clear();
     ^