编写题解 2351: 信息学奥赛一本通T1439-传送带

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<string>
#include<cstring>
#include<cmath>
#include<ctime>
#include<algorithm>
#include<utility>
#include<stack>
#include<queue>
#include<vector>
#include<set>
#include<map>
#include<bitset>
#define PI acos(-1.0)
#define INF 0x3f3f3f3f
#define LL long long
#define Pair pair<int,int>
const double EPS = 1E-10;
const int MOD = 1E9+7;
const int N = 10000+5;
const int dx[] = {-1,1,0,0,-1,-1,1,1};
const int dy[] = {0,0,-1,1,-1,1,-1,1};
using namespace std;
struct Node{
    double x,y;
    Node(){}
    Node(double x,double y):x(x),y(y){}
}a,b,c,d;
double p,q,r;
double getDis(double x1,double y1,double x2,double y2){
    return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
}
double judge(Node e){
    Node left(c.x,c.y),right(d.x,d.y);
    int times=100;//控制三分次数
    while(times--){
        Node lmid,rmid;
        lmid.x=left.x+(right.x-left.x)/3;
        lmid.y=left.y+(right.y-left.y)/3;
        rmid.x=right.x-(right.x-left.x)/3;
        rmid.y=right.y-(right.y-left.y)/3;
        double dis1=getDis(lmid.x,lmid.y,d.x,d.y)/q+getDis(lmid.x,lmid.y,e.x,e.y)/r;
        double dis2=getDis(rmid.x,rmid.y,d.x,d.y)/q+getDis(rmid.x,rmid.y,e.x,e.y)/r;
 
        if(dis1<dis2){
            right.x=rmid.x;
            right.y=rmid.y;
        }
        else{
            left.x=lmid.x;
            left.y=lmid.y;
        }
    }
    return getDis(left.x,left.y,d.x,d.y)/q+getDis(left.x,left.y,e.x,e.y)/r+getDis(e.x,e.y,a.x,a.y)/p;
 
}
int main(){
    scanf("%lf%lf",&a.x,&a.y);
    scanf("%lf%lf",&b.x,&b.y);
    scanf("%lf%lf",&c.x,&c.y);
    scanf("%lf%lf",&d.x,&d.y);
    scanf("%lf%lf%lf",&p,&q,&r);
 
    Node left(a.x,a.y),right(b.x,b.y);
    int times=100;//控制三分次数
    while(times--){
        Node lmid,rmid;
        lmid.x=left.x+(right.x-left.x)/3;
        lmid.y=left.y+(right.y-left.y)/3;
        rmid.x=right.x-(right.x-left.x)/3;
        rmid.y=right.y-(right.y-left.y)/3;
 
        if(judge(lmid)<judge(rmid)){
            right.x=rmid.x;
            right.y=rmid.y;
        }
        else{
            left.x=lmid.x;
            left.y=lmid.y;
        }
    }
    printf("%.2lf",judge(left));
 
    return 0;
}