View Compilation Error

0_0_25675703_1128.cpp:154:1: error: 'vector' does not name a type
 vector<int> v;
 ^
0_0_25675703_1128.cpp: In function 'void prin(int)':
0_0_25675703_1128.cpp:159:24: error: 'v' was not declared in this scope
     if(val[rt] != INF) v.push_back(val[rt]);//printf("%d ", val[rt]);
                        ^
0_0_25675703_1128.cpp: In function 'int main()':
0_0_25675703_1128.cpp:196:28: error: 'v' was not declared in this scope
         for(int i = 0; i < v.size(); ++i) {
                            ^
0_0_25675703_1128.cpp:200:9: error: 'v' was not declared in this scope
         v.clear();
         ^