View Compilation Error

0_0_26291006_31139.cpp: In function 'int main()':
0_0_26291006_31139.cpp:15:35: error: 'strlen' was not declared in this scope
   printf("%d\n", LCS(s1, strlen(s1), s2, strlen(s2)));
                                   ^
0_0_26291006_31139.cpp: In function 'int LCS(char*, int, char*, int)':
0_0_26291006_31139.cpp:22:26: error: 'memset' was not declared in this scope
  memset(dp, 0, sizeof(dp));
                          ^