Submission #1058127

#	Time	Username	Problem	Language	Result	Execution time	Memory
1058127		Alihan_8	Sightseeing in Kyoto (JOI22_kyoto)	C++17	40 / 100	330 ms	1048576 KiB

kyoto

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

const int inf = 1e15;

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

	int h, w; cin >> h >> w;
	
	vector <int> a(h), b(w);
	
	for ( auto &u: a ) cin >> u;
	
	for ( auto &u: b ) cin >> u;
	
	auto get = [&](vector <int> a){
		int n = a.size();
			
		vector <int> prfmin(n + 1), sufmin(n + 2);
		
		prfmin[0] = sufmin[n + 1] = inf;
		
		for ( int i = 0; i < n; i++ ){
			prfmin[i + 1] = min(prfmin[i], a[i]);
		}
		
		for ( int i = n; i > 0; i-- ){
			sufmin[i] = min(sufmin[i + 1], a[i - 1]);
		}
		
		vector <int> p;
		
		for ( int i = 0; i < n; i++ ){
			if ( max(prfmin[i], sufmin[i + 2]) <= a[i] ){
				continue;
			} p.pb(i);
		}
		
		return p;
	};
	
	auto idxA = get(a); h = idxA.size();
	auto idxB = get(b); w = idxB.size();
	
	vector <vector<int>> dp(h, vector <int> (w, inf));
	
	dp[0][0] = 0;
	
	for ( int i = 0; i < h; i++ ){
		for ( int j = !i; j < w; j++ ){
			int opt = inf;
			
			if ( i > 0 ) chmin(opt, b[idxB[j]] * (idxA[i] - idxA[i - 1]) + dp[i - 1][j]);
			if ( j > 0 ) chmin(opt, a[idxA[i]] * (idxB[j] - idxB[j - 1]) + dp[i][j - 1]);
			
			dp[i][j] = opt;
		}
	}
	
	cout << dp[h - 1][w - 1];

    cout << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 0 / 60