View Compilation Error

0_0_17089251_10719.cpp: In function 'void init()':
0_0_17089251_10719.cpp:20:21: error: 'sort' was not declared in this scope
     sort(r, r+n, cmp);
                     ^
0_0_17089251_10719.cpp: In function 'void solve()':
0_0_17089251_10719.cpp:23:47: error: 'memset' was not declared in this scope
     int i=0, last=0; memset(cor, 0, sizeof cor);
                                               ^