Submission #176030

#	Time	Username	Problem	Language	Result	Execution time	Memory
176030		maskoff	Bigger segments (IZhO19_segments)	C++14	0 / 100	4 ms	376 KiB

segments

#include <bits/stdc++.h>
 
#define file ""

#define all(x) x.begin(), x.end()

#define sc second
#define fr first

#define pb push_back
#define mp make_pair

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int inf = 1e9;
const int MOD = 1e9 + 7;
                                                                 
int main() {
#ifndef ONLINE_JUDGE
    freopen(file".in", "r", stdin);
    freopen(file".out", "w", stdout);  
#endif                                                   
    ios_base::sync_with_stdio(false);
  	cin.tie(nullptr);
  	int n;
  	cin >> n;
  	vector<ll> a(n + 1);
  	vector<ll>  pref(n + 1);
  	for (int i = 1; i <= n; i++)
  		cin >> a[i];
  	for (int i = 1; i <= n; i++)
  		pref[i] = pref[i - 1] + a[i];
  	vector<pair<ll, ll>> d(n + 1);
  	map<ll, pair<ll, ll>> ans;
  	vector<ll> all;
  	for (int i = 1; i <= n; i++) {
  		auto x = upper_bound(all.begin(), all.end(), pref[i]) - all.begin();
  		if (x == 0)	{
  			all.pb(pref[i] * 2);
  			ans[pref[i] * 2].fr = 1;
  			ans[pref[i] * 2].sc = pref[i];
  			continue;
  		}        
  		x--;
  		d[i].fr = ans[all[x]].fr + 1;
  		d[i].sc = pref[i] - ans[all[x]].sc;
  		if (ans[all.front()].fr < d[i].fr || (ans[all.front()].sc == d[i].fr && ans[all.front()].sc < d[i].sc)) {
  		 	all.pb(d[i].sc + pref[i]);
  		 	ans[d[i].sc + pref[i]].fr = d[i].fr;
  		 	ans[d[i].sc + pref[i]].sc = pref[i];
  		}                                    
  	}
  	cout << d[n].fr;
    return false;
}               

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:23:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen(file".in", "r", stdin);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:24:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen(file".out", "w", stdout);  
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27