View Compilation Error

0_0_22849908_3402.cpp:15:9: error: 'vector' does not name a type
 typedef vector<int> vint;
         ^
0_0_22849908_3402.cpp:16:1: error: 'vector' does not name a type
 vector <vint> G;
 ^
0_0_22849908_3402.cpp: In function 'void Insert(int, int)':
0_0_22849908_3402.cpp:19:5: error: 'G' was not declared in this scope
     G[a].push_back(b);
     ^