View Compilation Error

0_0_14590018_1528.cpp: In function 'bool subs(char*, char*)':
0_0_14590018_1528.cpp:10:22: error: 'strlen' was not declared in this scope
     int lx = strlen(x),
                      ^
0_0_14590018_1528.cpp:13:13: error: 'ly' was not declared in this scope
     if(lx > ly) return 0;
             ^
0_0_14590018_1528.cpp:14:12: error: 'px' was not declared in this scope
     for(;x[px];px++){
            ^
0_0_14590018_1528.cpp:15:26: error: 'py' was not declared in this scope
         while(x[px] != y[py] && y[py+1]) py++;
                          ^
0_0_14590018_1528.cpp:16:23: error: 'py' was not declared in this scope
         if(x[px] != y[py]) return false;
                       ^
0_0_14590018_1528.cpp:17:9: error: 'py' was not declared in this scope
         py++;
         ^