View Compilation Error

0_0_25418812_22012.cpp:6:9: error: 'pair' does not name a type
 typedef pair<int,int> Pi;
         ^
0_0_25418812_22012.cpp:7:9: error: 'vector' does not name a type
 typedef vector<int> Vi;
         ^
0_0_25418812_22012.cpp:8:9: error: 'map' does not name a type
 typedef map<int,int> Mii;
         ^
0_0_25418812_22012.cpp: In function 'int main()':
0_0_25418812_22012.cpp:28:34: error: 'scanf' was not declared in this scope
     while(scanf("%d%d%d",&n,&m,&k)!=EOF)
                                  ^
0_0_25418812_22012.cpp:28:37: error: 'EOF' was not declared in this scope
     while(scanf("%d%d%d",&n,&m,&k)!=EOF)
                                     ^
0_0_25418812_22012.cpp:32:23: error: 'sort' was not declared in this scope
         sort(a,a+n,cmp);
                       ^
0_0_25418812_22012.cpp:34:26: error: 'printf' was not declared in this scope
         printf("%d\n",ans);
                          ^