View Compilation Error

0_0_24566737_9949.cpp: In function 'int main()':
0_0_24566737_9949.cpp:27:29: error: 'strlen' was not declared in this scope
           int len1=strlen(s1);  
                             ^
0_0_24566737_9949.cpp:29:33: error: 'memset' was not declared in this scope
           memset(dp,0,sizeof(dp));  
                                 ^