Piggy-Bank 完全背包问题

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http://acm.hdu.edu.cn/showproblem.php?pid=1114

完全背包求最小值

常规解法超时（没优化）


#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<vector>
#include<cmath>
#include<stdlib.h>
#include<iomanip>
#include<list>
#include<deque>
#include<map>
#include <stdio.h>
#include <queue>

#define maxn 100000+5
#define ull unsigned long long
#define ll long long
#define reP(i,n) for(i=1;i<=n;i++)
#define rep(i,n) for(i=0;i<n;i++)
#define cle(a) memset(a,0,sizeof(a))
#define mod 90001
#define PI 3.141592657

const ull inf = 1LL << 61;
const double eps=1e-5;

using namespace std;

bool cmp(int a,int b){
    return a>b;
}
int val[10005],w[10005],dp[10005][10005];
int n,n1,n2,V;
int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    int t;
    cin>>t;
    while(t--)
    {
        cin>>n1>>n2;
        V=n2-n1;
        cin>>n;
        for(int i=1;i<=n;i++)
          scanf("%d%d",&val[i],&w[i]);

            for(int i=0;i<=n;i++)
              for(int j=0;j<=V;j++)
                 dp[i][j]=maxn;
                    dp[0][0]=0;val[0]=0;
                    
            for(int i=1;i<=n;i++)
                for(int j=0;j<=V;j++)
                    for(int k=0;k*w[i]<=j;k++)
                dp[i][j]=min(dp[i][j],dp[i-1][j-k*w[i]]+k*val[i]);
                if(dp[n][V]!=maxn)cout<<"The minimum amount of money in the piggy-bank is "<<dp[n][V]<<"."<<endl;
                else cout<<"This is impossible."<<endl;
    }
    return 0;
}

优化方法


#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<vector>
#include<cmath>
#include<stdlib.h>
#include<iomanip>
#include<list>
#include<deque>
#include<map>
#include <stdio.h>
#include <queue>

#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<vector>
#include<cmath>
#include<stdlib.h>
#include<iomanip>
#include<list>
#include<deque>
#include<map>
#include <stdio.h>
#include <queue>

#define maxn 999999999
#define ull unsigned long long
#define ll long long
#define reP(i,n) for(i=1;i<=n;i++)
#define rep(i,n) for(i=0;i<n;i++)
#define cle(a) memset(a,0,sizeof(a))
#define mod 90001
#define PI 3.141592657
#define INF 999999999
const ull inf = 1LL << 61;
const double eps=1e-5;

using namespace std;

bool cmp(int a,int b){
    return a>b;
}
int val[10005],vol[10005];
int dp[10005];
int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    int t;
    int st,ed,num;
    cin>>t;
    while(t--)
    {
        cin>>st>>ed;
        int V=ed-st;
        cle(vol);cle(val);
        cin>>num;
        cle(val);cle(vol);
        for(int i=1;i<=num;i++)
        {
           scanf("%d%d",&val[i],&vol[i]);
        }
        for(int i=1;i<=V;i++)
            dp[i]=INF;
            dp[0]=0;

        for(int i=1;i<=num;i++)
            for(int j=vol[i];j<=V;j++)
                dp[j]=min(dp[j],dp[j-vol[i]]+val[i]);
                if(dp[V]==INF)cout<<"This is impossible."<<endl;
                else
                cout<< "The minimum amount of money in the piggy-bank is "<<dp[V]<<"."<<endl;
    }
    return 0;
}