Submission #671566

#	Time	Username	Problem	Language	Result	Execution time	Memory
671566		Baytoro	Divide and conquer (IZhO14_divide)	C++17	0 / 100	0 ms	212 KiB

divide

#include <bits/stdc++.h>
using namespace std;
#define ios ios::sync_with_stdio(false); cin.tie(NULL);
#define pb push_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define fr first
#define sc second
#define int long long
#define endl '\n'
void fopn(string name){
	freopen((name+".in").c_str(),"r",stdin);
	freopen((name+".out").c_str(),"w",stdout);
}
const int INF=1e9+9,mod=1e9+7;

void solve(){
	int n,m;
	cin>>n;
	vector<int> x(n+1),g(n+1),d(n+1),suf(n+1);
	for(int i=1;i<=n;i++)
		cin>>x[i]>>g[i]>>d[i];
	for(int i=1;i<=n;i++){
		d[i]+=d[i-1];
		g[i]+=g[i-1];
	}
	suf[n]=d[n]-x[n];
	for(int i=n-1;i>=0;i--){
		suf[i]=max(suf[i+1],d[i]-x[i]);
	}
	for(int i=0;i<=n;i++)
		suf[i]=-suf[i];
	int res=0;
	/*for(int i=1;i<=n;i++)
		cout<<suf[i]<<' ';
	cout<<endl;*/
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			x[j]-=x[i];
			d[j]-=d[i-1];
		}
		suf[n]=d[n]-x[n];
		for(int j=n-1;j>=0;j--){
			suf[j]=max(suf[j+1],d[j]-x[j]);
		}
		for(int j=0;j<=n;j++)
			suf[j]=-suf[j];
		/*for(int j=1;j<=n;j++)
			cout<<suf[j]<<' ';
		cout<<endl;*/
		int l=i,r=(upper_bound(suf.begin()+i,suf.end(),0)-suf.begin())-1;
		
		//cout<<l<<' '<<r<<endl;
		res=max(g[r]-g[l-1],res);
	}
	cout<<res;
	
}
main(){
	ios;
	int T=1;
	//cin>>T;
	while(T--){
		solve();
	}
}

Compilation message (stderr)

divide.cpp: In function 'void solve()':
divide.cpp:18:8: warning: unused variable 'm' [-Wunused-variable]
   18 |  int n,m;
      |        ^
divide.cpp: At global scope:
divide.cpp:59:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   59 | main(){
      | ^~~~
divide.cpp: In function 'void fopn(std::string)':
divide.cpp:12:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |  freopen((name+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
divide.cpp:13:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |  freopen((name+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 17
• Subtask 2: 0 / 31
• Subtask 3: 0 / 52