View Compilation Error

0_0_20972128_25438.cpp: In function 'void init()':
0_0_20972128_25438.cpp:17:32: error: 'memset' was not declared in this scope
     memset(head,-1,sizeof(head));
                                ^
0_0_20972128_25438.cpp: In function 'void tarjan(int)':
0_0_20972128_25438.cpp:38:37: error: 'min' was not declared in this scope
             low[u]=min(low[u],low[v]);
                                     ^
0_0_20972128_25438.cpp: In function 'void solve()':
0_0_20972128_25438.cpp:73:28: error: 'printf' was not declared in this scope
     printf("%d\n",(ans+1)/2);
                            ^
0_0_20972128_25438.cpp: In function 'int main()':
0_0_20972128_25438.cpp:77:30: error: 'scanf' was not declared in this scope
     while(~scanf("%d%d",&n,&m))
                              ^