View Compilation Error

0_0_32428929_695.cpp: In function 'int main()':
0_0_32428929_695.cpp:28:32: error: 'strlen' was not declared in this scope
   int cur = 0, len = strlen(std), end = strlen(str);
                                ^
0_0_32428929_695.cpp:30:23: error: invalid operands of types 'int' and '<unresolved overloaded function type>' to binary 'operator<'
   for (int i = 0; i < end; i++) {
                       ^