View Compilation Error

0_0_17592323_15982.cpp: In function 'int main()':
0_0_17592323_15982.cpp:57:32: error: 'scanf' was not declared in this scope
     while (scanf("%d%d", &m, &n) == 2) {  
                                ^
0_0_17592323_15982.cpp:62:40: error: 'sort' was not declared in this scope
         sort(sorted + 1, sorted + 1 + m);  
                                        ^
0_0_17592323_15982.cpp:66:51: error: 'printf' was not declared in this scope
             printf("%d\n", query(a, b, k, 1, m, 0));  
                                                   ^