luogu_1016 旅行家的预算

#include <bits/stdc++.h>
using namespace std;
double dist,p[10],d[10],v1,c,t,ans,r[10];
int n,now;

int min(){
    double minn=100000000000; int j;
    for(int i=0;i<now;i++)if(r[i]!=0 && minn>p[i])minn=p[i],j=i;
    return j;
}

int main(){
    scanf("%lf%lf%lf%lf%d",&dist,&c,&t,&p[0],&n);
    r[0]=c;
    for(int i=1;i<=n;i++){scanf("%lf%lf",&d[i],&p[i]); r[i]=c;}
    for(int i=1;i<=n;i++){
        if(c*t*i<d[i]){puts("No Solution"); return 0;}
        double need=(d[i]-d[i-1])/t; now=i;
        for(int j=0;j<i;j++){
            if(need==0)break;
            int minn=min();
            if(r[minn]>=need){
                r[minn]-=need;
                ans+=p[minn]*need;
                need=0;
            }
            else {
                need-=r[minn];
                ans+=r[minn]*p[minn];
                r[minn]=0;
            }
        }
    }
    if(c*t*(n+1)<dist){puts("No Solution"); return 0;}
    dist=dist-d[n];
    double need=dist/t; now=n+1;
    for(int j=0;j<=n;j++){
        if(need==0)break;
        int minn=min();
        if(r[minn]>=need){
            r[minn]-=need;
            ans+=p[minn]*need;
            need=0;
        }
        else {
            need-=r[minn];
            ans+=r[minn]*p[minn];
            r[minn]=0;
        }
    }
    printf("%.2f
",ans);
    return 0;
}