Submission #336318

#	Time	Username	Problem	Language	Result	Execution time	Memory
336318		tengiz05	Bigger segments (IZhO19_segments)	C++17	37 / 100	618 ms	133484 KiB

segments

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define PI acos(-1)
#define ld long double
const int mod = 1e9+7, N = 5005, inf = 1e18;
int msb(int val){return sizeof(int)*8-__builtin_clzll(val);}
int a[N], n, m, k;
vector<pii> dp[N];
int pr[N];
vector<int> pm[N];
void solve(int test_case){
	int i, j;
	cin >> n;
	for(i=1;i<=n;i++){
		cin >> a[i];
		pr[i]=a[i];pr[i]+=pr[i-1];
	}
	for(i=1;i<=n;i++){
		dp[i].pb({pr[i], 1});
		dp[i].pb({inf, -213234684});
		pm[i].pb(dp[i][0].ss);
		for(j=1;j<dp[i].size();j++)pm[i].pb(max(pm[i].back(), dp[i][j].ss));
	}
	for(i=2;i<=n;i++){
		for(j=1;j<i;j++){
			int s = pr[i]-pr[j];
			int pos = upper_bound(all(dp[j]), pii{s+1,-1})-dp[j].begin();pos--;
		/*	cout << "the sum is " << s << '\n';
			cout << dp[j][pos+1].ff << " <- was this\n"; 
			cout << pos << '\n';*/
			int mx=0;
			if(pos<0)continue;
		/*	bool f = false;
			//if(i == 5)cout << s << '\n';
			for(k=0;k<=pos;k++){
				if(dp[j][k].ff > s)continue;
				mx = max(mx, dp[j][k].ss);f=true;
				//if(i==5)cout << dp[j][k].ff << ' ' << dp[j][k].ss << '\n';
			}*/
			int mx2 = pm[j][pos];
		//	cout << mx << ' ' << mx2 << '\n';
			dp[i].pb({s, mx2+1});
		}sort(all(dp[i]));
		pm[i].clear();
		pm[i].pb(dp[i][0].ss);
		for(j=1;j<dp[i].size();j++)pm[i].pb(max(pm[i].back(), dp[i][j].ss));
	}
/*	for(i=1;i<=n;i++){
		cout << "doing " << i<< '\n';
		for(auto [x, y] : dp[i]){
			cout << x << ' ' << y << '\n';
		}
	}*/
	int ans = 1;
	for(auto [x, y] : dp[n]){
		ans = max(ans, y);
	} 
	cout << ans << '\n';
	return;
}

signed main(){
	FASTIO;
#define MULTITEST 0
#if MULTITEST
	int ___T;
	cin >> ___T;
	for(int T_CASE = 1; T_CASE <= ___T; T_CASE++)
		solve(T_CASE);
#else
	solve(1);
#endif
	return 0;
}

Compilation message (stderr)

segments.cpp: In function 'void solve(long long int)':
segments.cpp:29:12: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   for(j=1;j<dp[i].size();j++)pm[i].pb(max(pm[i].back(), dp[i][j].ss));
      |           ~^~~~~~~~~~~~~
segments.cpp:38:8: warning: unused variable 'mx' [-Wunused-variable]
   38 |    int mx=0;
      |        ^~
segments.cpp:53:12: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |   for(j=1;j<dp[i].size();j++)pm[i].pb(max(pm[i].back(), dp[i][j].ss));
      |           ~^~~~~~~~~~~~~

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