Submission #256388

#	Time	Username	Problem	Language	Result	Execution time	Memory
256388		Saboon	Vim (BOI13_vim)	C++14	50 / 100	47 ms	1436 KiB

vim

#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef long long ll;
 
const int maxn = 500 + 10;

int nex[maxn][12];
int dp[maxn][maxn];
int pd[maxn];

int main(){
	ios_base::sync_with_stdio(false);
	int n;
	string s;
	cin >> n >> s;
	for (int i = 0; i < 10; i++){
		int last = -1;
		for (int j = n-1; j >= 0; j--){
			if (last == -1)
				nex[j][i] = j;
			else
				nex[j][i] = last;
			if ((int)(s[j] - 'a') == i and s[j] != 'e')
				last = j;
		}
	}
	vector<int> e;
	for (int i = 0; i < n; i++)
		if (s[i] == 'e')
			e.push_back(i);
	if (e.empty())
		return cout << 0 << endl, 0;
	int m = e.size();
	memset(dp, 63, sizeof dp);
	dp[0][0] = 0;
	for (int j = 0; j < m; j++){
		memset(pd, 63, sizeof pd);
		if (j > 0)
			pd[e[j-1]+1] = 0;
		else
			pd[0] = 0;
		for (int i = 0; i < n; i++)
			for (int c = 0; c < 10; c++)
				if (nex[i][c] != i)
					pd[nex[i][c]] = min(pd[nex[i][c]], pd[i] + 2);
		
		for (int i = j; i < m; i++){
			int it = i;
			int idx = (j == 0 ? 0 : e[j-1]+1);
			for (; idx < n; idx ++){
				if (s[idx] == 'e')
					continue;
				while (it < m and e[it] < idx)
					it ++;
				if (it == i)
					continue;
				dp[it][i+1] = min(dp[it][i+1], dp[i][j] + pd[idx] + (idx-e[i]) + (it-i));
			}
		}
	}
	int answer = 4*n;
	for (int i = 1; i <= m; i++)
		answer = min(answer, dp[m][i]);
	cout << answer << endl;
}

• Subtask 1: 50 / 50
• Subtask 2: 0 / 10
• Subtask 3: 0 / 40