UVA - 1336(考虑未来费用)

来源：互联网发布：jymusic源码编辑：程序博客网时间：2024/05/08 15:28
#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>using namespace std;#define INF 2000000000const int maxn = 1005;int n,x,add[maxn],cost[maxn],posi[maxn];double sum[maxn],v;struct node{int x,y,z;bool operator < (const node& rhs) const{return x < rhs.x;}}a[maxn];double Sum(int i,int j){return sum[j] - sum[i-1];}double d[maxn][maxn][2];bool vis[maxn][maxn][2];double dp(int i,int j,int p){if(vis[i][j][p]) return d[i][j][p];vis[i][j][p] = true;if(i==1 && j==n) return d[i][j][p] = 0;double& ans = d[i][j][p];bool flag =false;if(i > 1) { flag=true;   double t = (posi[p==0 ? i:j] - posi[i-1])*1.0/v;   ans =dp(i-1,j,0)+(Sum(1,i-1)+Sum(j+1,n))*t+cost[i-1];}if(j < n) {   double t = (posi[j+1] - posi[p==0 ? i:j])*1.0/v;   if(flag) ans = min(ans,dp(i,j+1,1)+(Sum(1,i-1)+Sum(j+1,n))*t+cost[j+1]);   else ans =dp(i,j+1,1)+(Sum(1,i-1)+Sum(j+1,n))*t+cost[j+1];}return ans;}int c;int main(){    while(scanf("%d %lf %d",&n,&v,&x)==3){        if(!n&&!v&&!x) break;        for(int i=1;i<=n;i++) {             scanf("%d %d %d",&a[i].x,&a[i].y,&a[i].z);        }        sort(a+1,a+n+1);        sum[0] = 0; c=0;        for(int i=1;i<=n;i++){            posi[i] = a[i].x; cost[i] = a[i].y; add[i] = a[i].z;            sum[i] = sum[i-1] + add[i];        }        memset(vis,false,sizeof(vis));        double res  = INF;        for(int i=1;i<=n;i++) {              double t =(posi[i] - x)*1.0/v;              if(posi[i] > x){ res = min(res,dp(i,i,0)+Sum(1,n)*t+cost[i]);              break;              }        }        for(int i=n;i>=1;i--) {              double t =(x - posi[i])*1.0/v;                if(posi[i] < x){ res = min(res,dp(i,i,0)+Sum(1,n)*t+cost[i]);                break;                }        }        printf("%d\n",(int)(res));    }    return 0;}
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