oj.uz

Submission #156821

# Submission time Handle Problem Language Result Execution time Memory
156821 2019-10-07T15:17:30 Z jhnah917 Split the sequence (APIO14_sequence) C++14
0 / 100
 18 ms 4712 KB 
#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
using namespace std;
 
typedef long long ll;
typedef pair<ll, ll> p;
 
struct Line{
	ll a, b, c;
	ll get(ll x){
		return a*x+b;
	}
};
 
struct CHT{
	vector<Line> stk;
	int idx = 1;
	
	void insert(Line v){
		if(stk.size() >= 1 && v.a == stk.back().a){
			stk.back().c = v.c;
			return;
		}
		while(stk.size() >= 2){
			if((stk.back().b - v.b)*(stk.back().a - stk[stk.size()-2].a) < (v.a - stk.back().a)*(stk[stk.size()-2].b - v.b)){
				stk.pop_back();
			}else break;
		}
		if(stk.back().a == v.a && stk.back().b <= v.b && v.c) return;
		stk.push_back(v);
	}
	
	p query(ll x){
		while(idx+1 < stk.size() && (stk[idx].b - stk[idx+1].b) < (stk[idx+1].a - stk[idx].a) * x) idx++;
		return {stk[idx].get(x), stk[idx].c};
	}
};
 
ll arr[101010];
ll sum[101010];
ll dp[2][101010];
int track[222][101010];
vector<int> ans;
 
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n, k; cin >> n >> k;
	for(int i=1; i<=n; i++) cin >> arr[i], sum[i] = sum[i-1] + arr[i];
	for(int i=1; i<=k; i++){
		CHT cht; cht.stk.reserve(101010); cht.insert({0, 0, 0});
		for(int j=1; j<=n; j++){
			auto now = cht.query(sum[j]);
			dp[i&1][j] = now.x;
			track[i][j] = now.y;
			cht.insert({sum[j], dp[(i-1)&1][j] - sum[j]*sum[j], j});
		}
	}
	
	cout << dp[k&1][n] << "\n";
	
	int now = n;
	ans.push_back(-1);
	for(int i=1; i<=k; i++){
		ans.push_back(track[k-i+1][now]);
		now = track[k-i+1][now];
	}
	sort(all(ans));
	for(int i=1; i<=k; i++){
		if(!ans[i]) ans[i] = 1;
		if(ans[i] <= ans[i-1]) ans[i] = ans[i-1] + 1;
	}
	for(int i=1; i<=k; i++) cout << ans[i] << " ";
}

Compilation message

sequence.cpp: In member function 'p CHT::query(ll)':
sequence.cpp:36:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(idx+1 < stk.size() && (stk[idx].b - stk[idx+1].b) < (stk[idx+1].a - stk[idx].a) * x) idx++;
         ~~~~~~^~~~~~~~~~~~

Subtask #1
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB contestant found the optimal answer: 108 == 108
2 Incorrect 2 ms 376 KB contestant didn't find the optimal answer: 774 < 999
3 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB declared answer doesn't correspond to the split scheme: declared = 1093398, real = 1091078
2 Halted 0 ms 0 KB -

Subtask #3
0 / 11.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB contestant didn't find the optimal answer: 314141646 < 610590000
2 Halted 0 ms 0 KB -

Subtask #4
0 / 17.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 488 KB contestant didn't find the optimal answer: 21297372 < 21503404
2 Halted 0 ms 0 KB -

Subtask #5
0 / 21.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 844 KB contestant didn't find the optimal answer: 1482064300 < 1818678304
2 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Incorrect 18 ms 4712 KB contestant didn't find the optimal answer: 14229199192 < 19795776960
2 Halted 0 ms 0 KB -