View Compilation Error

0_0_20017497_16925.cpp: In function 'void init()':
0_0_20017497_16925.cpp:26:18: error: 'sort' was not declared in this scope
  sort(r, r+n, cmp);
                  ^
0_0_20017497_16925.cpp: In function 'void solve()':
0_0_20017497_16925.cpp:30:44: error: 'memset' was not declared in this scope
  int i=0, last=0; memset(cor, 0, sizeof cor);
                                            ^