View Compilation Error

0_0_27033819_29769.cpp: In function 'bool bfs(int, int)':
0_0_27033819_29769.cpp:15:30: error: 'memset' was not declared in this scope
     memset(pre,-1,sizeof(pre));
                              ^
0_0_27033819_29769.cpp: In function 'int main()':
0_0_27033819_29769.cpp:60:29: error: 'scanf' was not declared in this scope
     while(scanf("%d%d",&m,&n)!=EOF)
                             ^
0_0_27033819_29769.cpp:60:32: error: 'EOF' was not declared in this scope
     while(scanf("%d%d",&m,&n)!=EOF)
                                ^
0_0_27033819_29769.cpp:63:29: error: 'memset' was not declared in this scope
         memset(r,0,sizeof(r));///
                             ^
0_0_27033819_29769.cpp:69:39: error: 'printf' was not declared in this scope
         printf("%d\n",EdmondsKarp(1,n));
                                       ^