View Compilation Error

0_0_16954675_15158.cpp: In function 'int main()':
0_0_16954675_15158.cpp:18:25: error: 'strtok' was not declared in this scope
   char *p=strtok(str," ");
                         ^
0_0_16954675_15158.cpp:21:31: error: 'strcmp' was not declared in this scope
   f(i,0,10)if(!strcmp(p,num[i])){t=i;break;}
                               ^
0_0_16954675_15158.cpp:35:26: error: 'strcmp' was not declared in this scope
       if(!strcmp(p,num[i]))
                          ^
0_0_16954675_15158.cpp:39:26: error: 'strcmp' was not declared in this scope
       if(!strcmp(p,num[i]))
                          ^
0_0_16954675_15158.cpp:45:24: error: 'strcmp' was not declared in this scope
     if(!strcmp(p,num[i]))
                        ^