[HDU 5090] Game with pearls (greedy)

Title Link: http://acm.hdu.edu.cn/showproblem.php?pid=5090

The main topic: give you n number, ask you to add a number of number of c*k (c>=0) can compose 1,2,3,4,5,..., n?

When I played this afternoon, I used a DFS to see which of the a[i] matches 1 to N.

Later tle to die ...

Think about it, first of all, if the number is a small number, then it can match a lot of kinds, so if you first match it out will be wasted, because it "ability" big.

So you can order, from big to small to match.

I don't know how to prove it in mathematical language.

1#include <iostream>2#include <cstdio>3#include <cstring>4#include <cstdlib>5#include <algorithm>6#include <map>7#include <Set>8#include <queue>9#include <string>Ten#include <functional> One using namespacestd; A  - intvis[ the]; - inta[ the]; the intn,k; - BOOLFlag; -  - intMain () { +     intM; -scanf"%d",&M); +  A      while(m--){ atFlag =true; -memset (Vis,0,sizeof(Vis)); -scanf"%d%d",&n,&K); -          for(intI=0; i<n;i++){ -scanf"%d",&a[i]); -         } inSort (a,a+n,greater<int>() ); -         inti; to          for(i=n;i>=1; i--){ +              for(intj=0; j<n;j++){ -                 if(a[j]<=i&&!vis[j]&& (i-a[j])%k==0 ){ thevis[j]=1; *                      Break; $                 }Panax Notoginseng             } -         } the          for(intI=0; i<n;i++){ +             if( !Vis[i]) { AFlag =0; the                  Break; +             } -         } $         if(flag) puts ("Jerry"); $         ElsePuts"Tom"); -     } -     return 0; the } - Wuyi /* the Ten - 3 1 Wu 1 2 3 - 3 1 About 0 0 0 $ 3 2 - 2 2 3 - 3 2 - 0 1 3 A 5 1 + 1 2 3) 4 5 the 6 2 - 1 2 3 4 5 5 $ */

[HDU 5090] Game with pearls (greedy)