Submission #292797

#	Time	Username	Problem	Language	Result	Execution time	Memory
292797		tmwilliamlin168	Shortcut (IOI16_shortcut)	C++14	0 / 100	1 ms	256 KiB

shortcut

#include "shortcut.h"
#include <bits/stdc++.h>
using namespace std;

#define ll long long

ll find_shortcut(int n, vector<int> l, vector<int> d, int c) {
	vector<ll> x(n);
	for(int i=0; i+1<n; ++i)
		x[i+1]=x[i]+l[i];
	ll lb=1, rb=2e15;
	while(lb<rb) {
		ll mb=(lb+rb)/2, a1=-1e18, a2=-1e18, a3=-1e18, b1=-1e18, b2=1e18, b3=-1e18, b4=1e18;
		vector<int> e{n-1};
		for(int i=n-2; ~i; --i)
			if(d[i]-x[i]>d[e.back()]-x[e.back()])
				e.push_back(i);
		for(int i=e.size()-1, j=0; j<n; ++j) {
			if(d[j]+x[j]<a1)
				continue;
			a1=d[j]+x[j];
			for(; ~i&&d[e[i]]-x[e[i]]>mb-a1; --i) {
				if(e[i]<j) {
					a2=max(d[e[i]]+x[e[i]], a2);
					a3=max(d[e[i]]-x[e[i]], a3);
				} else if(e[i]==j) {
					for(int k=i+1<e.size()?e[i+1]:0; k<j; ++k) {
						a2=max(d[k]+x[k], a2);
						a3=max(d[k]-x[k], a3);
					}
					break;
				}
			}
			b1=max(c-mb+d[j]+x[j]+a2, b1);
			b2=min(mb-c-d[j]+x[j]-a3, b2);
			b3=max(c-mb+d[j]-x[j]+a2, b3);
			b4=min(mb-c-d[j]-x[j]-a3, b4);
		}
		bool ok=0;
		for(int i=0, j1=n, j2=n, j3=0, j4=0; i<n; ++i) {
			for(; j1&&x[j1-1]>=b1-x[i]; --j1);
			for(; j2&&x[j2-1]>b2-x[i]; --j2);
			for(; j3<n&&x[j3]<b3+x[i]; ++j3);
			for(; j4<n&&x[j4]<=b4+x[i]; ++j4);
			ok|=max(j1, j3)<min(j2, j4);
		}
		if(ok)
			rb=mb;
		else
			lb=mb+1;
	}
	return lb;
}

Compilation message (stderr)

shortcut.cpp: In function 'long long int find_shortcut(int, std::vector<int>, std::vector<int>, int)':
shortcut.cpp:27:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |      for(int k=i+1<e.size()?e[i+1]:0; k<j; ++k) {
      |                ~~~^~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3