ZOJ3469 Food Delivery

Food Delivery

 ZOJ - 3469 

题意：外卖送饭给N个顾客，要求他们不满度和最小，没人不满度=等待时间*耐心值

#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;
#define maxn 1010
int n,x,v,dp[maxn][maxn][3],sum[maxn];
struct node{
    int x,b;
}a[maxn];
int cmp(node u,node v){
    return u.x<v.x;
}
int main(){
    while(scanf("%d%d%d",&n,&v,&x)!=EOF){
        memset(dp,127/3,sizeof(dp));
        memset(a,0,sizeof(a));
        for(int i=1;i<=n;i++)scanf("%d%d",&a[i].x,&a[i].b);
        n++;a[n].x=x,a[n].b=0;
        sort(a+1,a+n+1,cmp);int tmp;
        for(int i=1;i<=n;i++)sum[i]=sum[i-1]+a[i].b;
        for(int i=1;i<=n;i++)if(a[i].x==x){tmp=i;break;}
        dp[tmp][tmp][0]=0,dp[tmp][tmp][0]=0;
        for(int i=tmp;i>=1;i--){
            for(int j=tmp;j<=n;j++){
                dp[i][j][0]=min(dp[i][j][0],dp[i+1][j][0]+(sum[n]-sum[j]+sum[i])*(a[i+1].x-a[i].x));
                dp[i][j][0]=min(dp[i][j][0],dp[i+1][j][1]+(sum[n]-sum[j]+sum[i])*(a[j].x-a[i].x));
                dp[i][j][1]=min(dp[i][j][1],dp[i][j-1][0]+(sum[n]-sum[j-1]+sum[i-1])*(a[j].x-a[i].x));
                dp[i][j][1]=min(dp[i][j][1],dp[i][j-1][1]+(sum[n]-sum[j-1]+sum[i-1])*(a[j].x-a[j-1].x));
            }
        }
        printf("%d\n",min(dp[1][n][0],dp[1][n][1])*v);
    }
}