View Compilation Error

0_0_18093381_1790.cpp:33:1: error: 'map' does not name a type
 map<double,int>::iterator it;
 ^
0_0_18093381_1790.cpp: In function 'LL solve1()':
0_0_18093381_1790.cpp:50:13: error: 'it' was not declared in this scope
         for(it = M.begin(); it != M.end(); it++)
             ^