View Compilation Error

0_0_33975701_17807.cpp:6:9: error: 'pair' does not name a type
 typedef pair<int, int> PII;
         ^
0_0_33975701_17807.cpp: In function 'int isPrime(int)':
0_0_33975701_17807.cpp:15:34: error: 'sqrt' was not declared in this scope
     n_sqrt = floor(sqrt((float) n));
                                  ^
0_0_33975701_17807.cpp:15:35: error: 'floor' was not declared in this scope
     n_sqrt = floor(sqrt((float) n));
                                   ^
0_0_33975701_17807.cpp: In function 'int main()':
0_0_33975701_17807.cpp:28:19: error: 'scanf' was not declared in this scope
     scanf("%d", &T);
                   ^
0_0_33975701_17807.cpp:42:25: error: 'printf' was not declared in this scope
             printf("W\n");
                         ^
0_0_33975701_17807.cpp:45:29: error: 'printf' was not declared in this scope
                 printf("W\n");
                             ^
0_0_33975701_17807.cpp:47:29: error: 'printf' was not declared in this scope
                 printf("L\n");
                             ^
0_0_33975701_17807.cpp:50:25: error: 'printf' was not declared in this scope
             printf("L\n");
                         ^