View Compilation Error

0_0_23636054_32554.cpp: In function 'int main()':
0_0_23636054_32554.cpp:37:34: error: 'memset' was not declared in this scope
         memset(dp, -1, sizeof(dp));
                                  ^
0_0_23636054_32554.cpp:38:32: error: 'strlen' was not declared in this scope
         cout << dfs(0, strlen(s) - 1, 26) << endl;
                                ^