P1016 旅行家的预算

链接：[Miku]（https://www.luogu.com.cn/problem/P1016）'

贪心，对于每一个点，优先跑到能到的点中第一个价格较原点低的，否则加满油跑到价格最低的一个

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<map> 
#define dou  double
using namespace std;
dou d1,c,d2,pp;
int n;
dou d[7];
dou p[7];
dou v;
 double x,y;
 double ans=99999999.0;
void dfs(int pos,double co,double le,int f){
	if(pos==n+1){
	printf("%.2lf",co-le*p[f]);
	exit(0); 
	}
	dou vv=d[pos]+v;
	for(int i=pos+1;i<=n+1&&d[i]<=vv;++i){
		if(p[i]<=p[pos]){
			dfs(i,co+double(d[i]-d[pos])/d2*p[pos],le,pos);
			return ;
		}
	}
	if(pos+1<=n+1&&d[pos+1]<=vv){
	int ppp=pos+1;
	for(int i=pos+1;i<=n+1&&d[i]<=vv;++i){
		if(p[i]<=p[ppp]){
			ppp=i;
		}
	} 
	dfs(ppp,co+double(c-le)*p[pos],c-(d[ppp]-d[pos])/d2,pos);
	return ;
}
}
int main(){
	scanf("%lf%lf%lf%lf%d",&d1,&c,&d2,&pp,&n);
	d[0]=0;
	p[0]=pp;
	v=c*d2;
	for(int i=1;i<=n;++i){
		scanf("%lf%lf",&d[i],&p[i]);
	}
	d[n+1]=d1;
	dfs(0,0.0,0,0);
	printf("No Solution");
	return 0;
}