View Compilation Error

0_0_10048668_23911.cpp: In function `int main()':
0_0_10048668_23911.cpp:16: error: `memset' undeclared (first use this function)
0_0_10048668_23911.cpp:16: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_10048668_23911.cpp: In function `void DFS(char*, int, int*)':
0_0_10048668_23911.cpp:31: error: `strlen' undeclared (first use this function)