View Compilation Error

0_0_22772225_25044.cpp: In function 'int solve()':
0_0_22772225_25044.cpp:28:51: error: 'upper_bound' was not declared in this scope
    int t = a + n - upper_bound(a, a + n, tmp, cmpL);
                                                   ^
0_0_22772225_25044.cpp: In function 'int main()':
0_0_22772225_25044.cpp:44:22: error: 'sort' was not declared in this scope
   sort(a, a + n, cmpL);
                      ^