View Compilation Error

0_0_23424439_28097.cpp: In function 'int check(char*)':
0_0_23424439_28097.cpp:4:16: error: 'strlen' was not declared in this scope
     if(strlen(s)<8||strlen(s)>16)
                ^
0_0_23424439_28097.cpp: In function 'int main()':
0_0_23424439_28097.cpp:41:24: error: 'scanf' was not declared in this scope
     while(scanf("%d",&m)==1)
                        ^
0_0_23424439_28097.cpp:48:27: error: 'printf' was not declared in this scope
             printf("YES\n");
                           ^
0_0_23424439_28097.cpp:50:26: error: 'printf' was not declared in this scope
             printf("NO\n");
                          ^