HDU 5339 Untitled

This question is obviously a check-in question, but I did not make the game, naked zero, really tragic ...

After looking at the main idea of the direct search on the line, just need to put them from the big to small sort after search, I did not think ... I don't want to say more.

At first I enumerate all the cases directly:

1#include <cstdio>2#include <cstring>3#include <vector>4#include <algorithm>5 using namespacestd;6 7 intb[ at],a;8 9InlineBOOLOkConstvector<int> &v,inta) {Ten     intLen =v.size (); One      for(inti = len-1; I >=0; --i) A         if(a% v[i] = =0)return 1; -         ElseA%=V[i]; -     return 0; the } -  - intMain () { -     intT,n; +scanf"%d",&t); -      while(t--) { +scanf"%d%d",&n,&a); A          for(inti =0; I < n; ++i) atscanf"%d", B +i); -Sort (b, B +n); -         intLimit = (1<< N)-1; -         BOOLFlag =0; -          for(inti =1; I <= limit; ++i) { -vector<int>v; in              for(intj =0; (1<< j) <= I; ++j) -                 if(I & (1<<j)) V.push_back (B[j]); to             if(ok (V, a)) { +printf"%d\n", V.size ()); -Flag =1; the                  Break; *             } $         }Panax Notoginseng         if(Flag = =0) puts ("-1"); -     } the     return 0; +}

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But found 700+ms, surprisingly slow, so I try to direct deep search, unexpectedly 78ms, sure enough fast!

1#include <cstdio>2#include <cstring>3#include <vector>4#include <algorithm>5 using namespacestd;6 Const intINF =0x3fffffff;7 8 intb[ at],ans,n;9 Ten voidDfsintIdintNuminta) { One     if(A = =0) { AAns =min (ans, num); -         return ; -     } the     if(ID > N)return ; -  -DFS (ID +1, Num +1AB[id]); -DFS (ID +1, Num, a); + } -  +InlineBOOLcmpintXinty) { A     returnX >y; at } -  - intMain () { -     intT, A; -scanf"%d",&t); -      while(t--) { inscanf"%d%d",&n,&a); -          for(inti =1; I <= N; ++i) toscanf"%d", B +i); +Sort (b +1, B + n +1, CMP); -Ans =inf; theDfs1,0, a); *printf"%d\n", ans = = inf? -1: ans); $     }Panax Notoginseng     return 0; -}

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On the internet to see a single pressure than my first version faster than:

1#include <cstdio>2#include <cstring>3#include <algorithm>4 using namespacestd;5 int ConstMAX =1<< A;6 int ConstINF =0x3fffffff;7 intb[ -], Sta[max];8 9 intLowbit (intx)Ten { One     returnX & (-x); A } -  - BOOLcmpintAintb) the { -     returnA >b; - } -  + intMain () - { +     intT; Ascanf"%d", &T); at      while(T--) -     { -memset (STA,0,sizeof(STA)); -         intN, A; -scanf"%d%d", &n, &a); -          for(inti =1; I <= N; i++) inscanf"%d", &b[i]); -Sort (b +1, B + n +1, CMP); to          for(inti =1; I <= N; i++) +sta[1<< (I-1)] =B[i]; -         intCNT, ans =INF; the          for(inti =1; I < (1<< N); i++) *         { $             intTMP =A;Panax NotoginsengCNT =0; -              for(intj = i; J >0; J-=Lowbit (j)) the             { +TMP%=Sta[lowbit (j)]; ACNT + +; the             } +             if(TMP = =0) -Ans =min (ans, cnt); $         } $         if(ans = =INF) -printf"-1\n"); -         Else theprintf"%d\n", ans); -     }Wuyi}

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Although it blew zero, the game still had to be played.

HDU 5339 Untitled