1342. Enterprise 夜

http://acm.timus.ru/problem.aspx?space=1&num=1342

简单DP

代码：

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<math.h>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<string>
#include<queue>
#include<stack>
#include <iomanip>
using namespace std;
#define LL long long
const int INF=0x3f3f3f3f;
const double FINF=1e12;
const int N=1005;
double ans[N][N];
int k[N];
double p[N],q[N];
int main()
{
    //freopen("data.in","r",stdin);
    int n,m;
    while(cin>>n>>m)
    {
        for(int i=1;i<=n;++i)
        cin>>k[i]>>p[i]>>q[i];
        for(int i=0;i<=n;++i)
        for(int j=0;j<=m;++j)
        if(j==0)
        ans[i][j]=0.0;
        else
        ans[i][j]=FINF;
        for(int i=1;i<=n;++i)
        for(int j=1;j<=m;++j)
        {
            double sum=0.0;
            double t=0.0;
            if(k[i]>1)
            t=(q[i]-p[i])/(k[i]-1);
            for(int l=0;l<=k[i]&&l<=m;++l)
            {
                if(l>0)
                sum+=(p[i]+(l-1)*t);
                ans[i][j]=min(ans[i][j],sum+ans[i-1][j-l]);
            }
        }
        if(ans[n][m]<FINF)
        printf("Minimum possible cost: %.2f\n",ans[n][m]);
        else
        {
            int w;
            for(w=m;w>=0;--w)
            if(ans[n][w]<FINF)
            break;
            printf("Maximum possible amount: %d\n",w);
            printf("Minimum possible cost: %.2f\n",ans[n][w]);
        }
    }
    return 0;
}