zju 1161 Gone Fishing
这个题是个经典的贪心题。
枚举走过的湖的个数x,最终将在湖x停下来,那么在走路上消耗的时间可以算出来t[1]+t[2]+...+t[n-1],在这个前提下,我们可以从一个湖瞬移到另外一个湖(这个是关键!!!)。为了掉的更多的鱼,我们每次都选择瞬移到与最多的湖去钓5分钟(可以通过优先队列来实现),这样得到的鱼肯定是最多的。
我做这个题一开始WA了N次,有下面2点必须要注意:
1)对于进入优先队列的比较操作,除了要比较湖中鱼的多少外,当鱼的数量相同时,要优先选择靠前的湖。
2)要考虑到有剩余时间不能用的情况,即鱼都钓完了,但是还有时间,这是要将剩余的时间都加到1号湖中。
3)最优时间的初始值不要设为0,因为最优值可能是0,这样的话最优钓鱼的方案得不到更新。
my code:
#include <iostream>
#include <queue>
using namespace std;
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
struct node {
int id;
int fn;
node() {}
node(int I,int F):id(I),fn(F) {}
};
bool operator<(const node& n1,const node& n2) {
if(n1.fn==n2.fn) return n1.id>n2.id;
return n1.fn<n2.fn;
}
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
priority_queue<node> q;
int n,h,maxfish,small;
int f[26],d[26],t[26],cnt[26],cntt[26];
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
int main() {
int tt,ca=0;
cin>>tt;
while(tt--) {
while(cin>>n) {
if(n==0) break;
cin>>h;
h=h*60;
for(int i=1;i<=n;i++) cin>>f[i];
for(int i=1;i<=n;i++) cin>>d[i];
for(int i=1;i<n;i++) cin>>t[i];
maxfish=-1;
for(int stop=1;stop<=n;stop++) {
memset(cntt,0,sizeof cntt);
while(!q.empty()) q.pop();
int spendonway=0;
for(int i=1;i<stop;i++) spendonway+=5*t[i];
for(int i=1;i<=stop;i++) {
if(f[i]>0)
q.push(node(i,f[i]));
}
int timetofish=h-spendonway;
int totalfish=0;
if(timetofish<5) continue;
while(timetofish>=5&&!q.empty()) {
node nt=q.top();
q.pop();
timetofish-=5;
totalfish+=nt.fn;
cntt[nt.id]+=5;
if(nt.fn>d[nt.id])
q.push(node(nt.id,nt.fn-d[nt.id]));
}
if(timetofish>0) cntt[1]+=timetofish;
if(maxfish<totalfish) {
maxfish=totalfish;
memcpy(cnt,cntt,sizeof cntt);
}
if(maxfish==totalfish) {
for(int i=1;i<=n;i++) {
if(cntt[i]==cnt[i]) continue;
if(cntt[i]>cnt[i]) {small=0;break;}
if(cntt[i]<cnt[i]) {small=1;break;}
}
if(small==0) {
memcpy(cnt,cntt,sizeof cntt);
}
}
}
if(ca++>0) cout<<endl;
cout<<cnt[1];
for(int i=2;i<=n;i++) cout<<", "<<cnt[i];
cout<<endl;
cout<<"Number of fish expected: "<<maxfish<<endl;
}
}
return 0;
}
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
枚举走过的湖的个数x,最终将在湖x停下来,那么在走路上消耗的时间可以算出来t[1]+t[2]+...+t[n-1],在这个前提下,我们可以从一个湖瞬移到另外一个湖(这个是关键!!!)。为了掉的更多的鱼,我们每次都选择瞬移到与最多的湖去钓5分钟(可以通过优先队列来实现),这样得到的鱼肯定是最多的。
我做这个题一开始WA了N次,有下面2点必须要注意:
1)对于进入优先队列的比较操作,除了要比较湖中鱼的多少外,当鱼的数量相同时,要优先选择靠前的湖。
2)要考虑到有剩余时间不能用的情况,即鱼都钓完了,但是还有时间,这是要将剩余的时间都加到1号湖中。
3)最优时间的初始值不要设为0,因为最优值可能是0,这样的话最优钓鱼的方案得不到更新。
my code:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)