View Compilation Error

0_0_25008742_30541.cpp:10:1: error: 'unordered_map' does not name a type
 unordered_map<ll,int>mp;
 ^
0_0_25008742_30541.cpp: In function 'void add(int, int, int)':
0_0_25008742_30541.cpp:12:5: error: 'mp' was not declared in this scope
     mp[v*1ll*(n+5)+root]=dis;
     ^
0_0_25008742_30541.cpp: In function 'int getdis(int, int)':
0_0_25008742_30541.cpp:15:12: error: 'mp' was not declared in this scope
     return mp[v*1ll*(n+5)+root];
            ^
0_0_25008742_30541.cpp: In function 'int main()':
0_0_25008742_30541.cpp:146:16: error: 'mp' was not declared in this scope
         init();mp.clear();
                ^