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加油事件的贪心选择模拟

#include
   
    #include
    
     #include
     
      typedef struct Station{	double dis;	double price;	bool operator<(const Station& other) const	{		return dis < other.dis;	}}Station;double unit_gas;int FindNeatestCheaperStation(int i, double gas, std::vector
      
       & s){	int num = s.size();	int min_index = i;	for(int j = i+1; j < num && s[j].dis-s[i].dis <= gas*unit_gas; ++j)	{		if(s[j].price < s[min_index].price)		{			min_index = j;			break;		}	}	return min_index;}int GetFastestStation(int i, double gas, std::vector
       
        & s){	int num = s.size();	int max_index = i;	for(int j = i+1; j < num && s[j].dis-s[i].dis <= gas*unit_gas; ++j)	{		max_index = j;	}	return max_index;}int main(){	double max_gas, total_dis;	int n;	while(scanf("%lf%lf%lf%d",&max_gas,&total_dis,&unit_gas,&n)!=EOF)	{		std::vector
        
          sVec(n); for(int i = 0; i < n; ++i) scanf("%lf %lf",&sVec[i].price,&sVec[i].dis); //sort station by distance std::sort(sVec.begin(), sVec.end()); Station vir; vir.dis = total_dis;//add destination as a virtual station in the end sVec.push_back(vir); //algorithm core if(n==0 || sVec[0].dis > 0)//special case printf("The maximum travel distance = 0.00\n"); else//greedy now { double remain_gas = 0.0; double cur_money = 0.0; int i; for(i = 0; i < n; ) { int index; //1. using remain gas find nearest cheaper station index = FindNeatestCheaperStation(i, remain_gas, sVec); if(index != i)//find a station else {//get there remain_gas -= (sVec[index].dis-sVec[i].dis)/unit_gas; i = index; continue; } //2. using max_gas find nearest cheaper station index = FindNeatestCheaperStation(i, max_gas, sVec); if(index != i)//find a station else {//get there cur_money += ((sVec[index].dis-sVec[i].dis)/unit_gas-remain_gas)*sVec[i].price; remain_gas = 0.0; i = index; continue; } //3. get the max_gas and go as far as possible index = GetFastestStation(i, max_gas, sVec); if(index != i) {//can get some where cur_money += (max_gas-remain_gas)*sVec[i].price; remain_gas = max_gas-(sVec[index].dis-sVec[i].dis)/unit_gas; i = index; continue; } else { printf("The maximum travel distance = %.2lf\n", sVec[i].dis+max_gas*unit_gas); break; } }//end of greedy if(i == n) printf("%.2lf\n", cur_money); } } return 0; }
        
       
      
     
    
   

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