View Compilation Error

0_0_29474031_3354.cpp: In function 'int getLCSlength(const char*, const char*)':
0_0_29474031_3354.cpp:17:22: error: 'strlen' was not declared in this scope
  int len1 = strlen(s1);
                      ^
0_0_29474031_3354.cpp: In function 'void getLCS(const char*, const char*, int, char*)':
0_0_29474031_3354.cpp:48:19: error: 'strlen' was not declared in this scope
  int i = strlen(s1);
                   ^
0_0_29474031_3354.cpp:51:30: error: 'memset' was not declared in this scope
  memset(flag1,0,sizeof(flag1));
                              ^