View Compilation Error

0_0_21941736_3233.cpp: In function 'int main()':
0_0_21941736_3233.cpp:43:19: error: 'gets' was not declared in this scope
     while(gets(str),*str)
                   ^
0_0_21941736_3233.cpp:46:25: error: 'scanf' was not declared in this scope
     while(scanf("%s",str)>0)
                         ^
0_0_21941736_3233.cpp:47:29: error: 'printf' was not declared in this scope
     printf("%d\n",query(str));
                             ^