题意: 给定油站的位置以及价格,要求要在汽车油量为零的情况下加到最便宜的油到达目的地
tip:贪心
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
const int inf = 99999999;
struct station {
double price, dis;
bool operator < (const struct station a)const{
return dis<a.dis;
}
};
int main() {
double cmax, d, davg;
int n;
scanf("%lf%lf%lf%d", &cmax, &d, &davg, &n);
vector<station> sta(n + 1);
sta[0] = {0.0, d};
for(int i = 1; i <= n; i++)
cin>>sta[i].price>>sta[i].dis;
sort(sta.begin(), sta.end());
double nowdis = 0.0, maxdis = 0.0, nowprice = 0.0, totalPrice = 0.0, leftdis = 0.0;
if(sta[0].dis != 0) {
printf("The maximum travel distance = 0.00");
return 0;
} else
nowprice = sta[0].price;
while(nowdis < d) {
maxdis = nowdis + cmax * davg;
double minPriceDis = 0, minPrice = inf;
int flag = 0;
for(int i = 1; i <= n && sta[i].dis <= maxdis; i++) {
if(sta[i].dis <= nowdis) continue;
if(sta[i].price < nowprice) {
totalPrice += (sta[i].dis - nowdis - leftdis) * nowprice / davg;
leftdis = 0.0;
nowprice = sta[i].price;
nowdis = sta[i].dis;
flag = 1;
break;
}
if(sta[i].price < minPrice) {
minPrice = sta[i].price;
minPriceDis = sta[i].dis;
}
}
if(flag == 0 && minPrice != inf) {
totalPrice += (nowprice * (cmax - leftdis / davg));
leftdis = cmax * davg - (minPriceDis - nowdis);
nowprice = minPrice;
nowdis = minPriceDis;
}
if(flag == 0 && minPrice == inf) {
nowdis += cmax * davg;
printf("The maximum travel distance = %.2lf", nowdis);
return 0;
}
}
printf("%.2lf", totalPrice);
return 0;
}