link:http://acm.hdu.edu.cn/showproblem.php?pid=2546
也算一个贪心的想法吧．
先把总钱数减去５，再把价值最大的挑出来．然后用０１背包．最终买下挑出来的那个价值最大的商品．这样的话，我就实现了最终用最少的钱数买了价值最多的商品，剩下钱数当然也是最少了．
1 #include <iostream> 2 #include <cstdio> 3 #include <cstdlib> 4 #include <cstring> 5 #include <cmath> 6 #include <cctype> 7 #include <algorithm> 8 #include <queue> 9 #include <deque> 10 #include <queue> 11 #include <list> 12 #include <map> 13 #include <set> 14 #include <vector> 15 #include <utility> 16 #include <functional> 17 #include <fstream> 18 #include <iomanip> 19 #include <sstream> 20 #include <numeric> 21 #include <cassert> 22 #include <ctime> 23 #include <iterator> 24 const int INF = 0x3f3f3f3f; 25 const int dir[8][2] = {{-1,0},{1,0},{0,-1},{0,1},{-1,-1},{-1,1},{1,-1},{1,1}}; 26 using namespace std; 27 int main(void) 28 { 29 ios::sync_with_stdio(false); 30 int n, V; 31 int c[1111], f[1111]; 32 #ifndef ONLINE_JUDGE 33 freopen("in.txt", "r", stdin); 34 #endif // ONLINE_JUDGE 35 while (cin>>n) 36 { 37 if(!n) break; 38 for (int i = 0; i < n; ++i) cin>>c[i]; 39 cin>>V; 40 V-=5; 41 if (V<0) 42 { 43 cout<<V+5<<endl; continue; 44 } 45 int tmp=-1, Max; 46 for (int i = 0; i <n; ++i) 47 if(tmp<c[i]) tmp=c[i], Max=i; 48 memset(f,0,sizeof(f)); 49 for (int i=0;i<n;++i) 50 { 51 if (i==Max) continue; 52 for (int v = V; v>=c[i]; --v) 53 { 54 f[v] = max(f[v], f[v-c[i]]+c[i]); 55 } 56 } 57 cout<<V+5-f[V]-c[Max]<<endl; 58 } 59 return 0; 60 }
囧
