View Compilation Error

0_0_13177649_4634.cpp: In function 'int main()':
0_0_13177649_4634.cpp:21:26: error: 'strcmp' was not declared in this scope
    if(strcmp(input,"Caps")==0){tag++;continue;}
                          ^
0_0_13177649_4634.cpp:22:24: error: 'strncpy' was not declared in this scope
    strncpy(temp,input,5),temp[5]='/0';
                        ^
0_0_13177649_4634.cpp:23:26: error: 'strcmp' was not declared in this scope
    if(strcmp(temp,"Shift")==0)
                          ^