View Compilation Error

0_0_6141256_23966.cpp: In function `int main()':
0_0_6141256_23966.cpp:13: error: `strlen' undeclared (first use this function)
0_0_6141256_23966.cpp:13: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6141256_23966.cpp:20: error: ISO C++ forbids comparison between pointer and integer