Submission #62172

#	Time	Username	Problem	Language	Result	Execution time	Memory
62172		KLPP	Bulldozer (JOI17_bulldozer)	C++14	20 / 100	2029 ms	63108 KiB

bulldozer

#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
typedef long long int lld;
typedef pair<pair<lld,lld>,lld> piii;
int cmp(pair<pair<lld,lld>,pair<int,int> > x, pair<pair<lld,lld>,pair<int,int> > y){
	if(x.first.first*y.first.second>x.first.second*y.first.first){
		return true;
	}return false;
}

int main(){
	int n;
	scanf("%d",&n);
	piii arr[n];
	for(int i=0;i<n;i++){
		scanf("%lld %lld %lld",&arr[i].first.first,&arr[i].first.second,&arr[i].second);
	}sort(arr,arr+n);
	lld ans=0;
	if(n==1){
		if(arr[0].second>0){
			cout<<arr[0].second<<endl;
			return 0;
		}cout<<0<<endl;
		return 0;
	}
	vector<pair<pair<lld,lld>,pair<int,int> > > array;
	for(int i=0;i<n;i++){
		for(int j=i+1;j<n;j++){
			pair<lld,lld> p1=pair<lld,lld>(arr[j].first.second-arr[i].first.second,arr[j].first.first-arr[i].first.first);
			
			array.push_back(pair<pair<lld,lld>,pair<int,int> >(p1,pair<int,int>(i,j)));
		}
	}sort(array.begin(),array.end(),cmp);
	/*for(int i=0;i<array.size();i++){
		cout<<array[i].first.first<<" "<<array[i].first.second<<" "<<array[i].second.first<<" "<<array[i].second.second<<endl;
	}*/	
	pair<int,int> changes[array.size()];
	for(int i=0;i<array.size();i++){
		changes[i].first=array[i].second.first;
		changes[i].second=array[i].second.second;
	}
	int per[n];
	for(int i=0;i<n;i++)per[i]=i;
	for(int i=0;i<array.size();i++){
		int x,y;
		for(int j=0;j<n;j++){
			if(per[j]==array[i].second.first)x=j;
			if(per[j]==array[i].second.second)y=j;
		}
		swap(per[x],per[y]);
		lld DP[n];
		lld zero=0;
		DP[0]=max(zero,arr[per[0]].second);
		ans=max(ans,DP[0]);
		for(int j=1;j<n;j++){
			DP[j]=max(zero,DP[j-1]+arr[per[j]].second);
			ans=max(ans,DP[j]);
		}
	}cout<<ans<<endl;
	
	

	return 0;
}

Compilation message (stderr)

bulldozer.cpp: In function 'int main()':
bulldozer.cpp:41:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<array.size();i++){
              ~^~~~~~~~~~~~~
bulldozer.cpp:47:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<array.size();i++){
              ~^~~~~~~~~~~~~
bulldozer.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
bulldozer.cpp:19:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld %lld %lld",&arr[i].first.first,&arr[i].first.second,&arr[i].second);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bulldozer.cpp:48:7: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   int x,y;
       ^
bulldozer.cpp:48:9: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   int x,y;
         ^

• Subtask 1: 0 / 5
• Subtask 2: 20 / 20
• Subtask 3: 0 / 35
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20