View Compilation Error

0_0_37173640_16590.cpp: In function 'void LCS()':
0_0_37173640_16590.cpp:11:38: error: 'memset' was not declared in this scope
 #define mem(a,b) memset(a,b,sizeof(a))
                                      ^
0_0_37173640_16590.cpp:27:2: note: in expansion of macro 'mem'
  mem(vis, 0);
  ^
0_0_37173640_16590.cpp: In function 'int main()':
0_0_37173640_16590.cpp:81:18: error: 'strlen' was not declared in this scope
   len1 = strlen(s), len2 = strlen(t);
                  ^