View Compilation Error

0_0_36555849_1587.cpp: In function 'int main()':
0_0_36555849_1587.cpp:16:25: error: 'memset' was not declared in this scope
   memset(dp,0,sizeof(dp));
                         ^
0_0_36555849_1587.cpp:30:43: error: 'sp' was not declared in this scope
      if(used) dp[j][used]=max(dp[j][used],sp[j-l[i]/2][used-1]+w[i]);
                                           ^