Submission #286176

#	Time	Username	Problem	Language	Result	Execution time	Memory
286176		reymontada61	Collecting Stamps 3 (JOI20_ho_t3)	C++14	15 / 100	2092 ms	145076 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;

#define int long long
int n, l;
const int MXN = 205;
int pos[MXN], by[MXN];

int dp[MXN][MXN][2][MXN];

priority_queue<pair<int, pair<pair<int, int>, pair<int, int>>>, vector<pair<int, pair<pair<int, int>, pair<int, int>>>>, greater<pair<int, pair<pair<int, int>, pair<int, int>>>>> proc;

bool can(int l, int r) {
	if (r + 1 == l) return true;
	if (l == 1 && r == n) return true;
	return false;
}

int prev(int x) {
	if (x == 1) return n;
	return x - 1;
}

int next(int x) {
	if (x == n) return 1;
	return x + 1;
}

signed main() {

	cin >> n >> l;
	for (int i=1; i<=n; i++) {
		cin >> pos[i];
	}
	for (int i=1; i<=n; i++) {
		cin >> by[i];
	}
	
	if (n == 1) {
		if (min(pos[1], l - pos[1]) <= by[1]) cout << 1 << endl;
		else cout << 0 << endl;
		return 0;
	}
	
	for (int i=1; i<=n; i++) {
		for (int j=1; j<=n; j++) {
			for (int f=0; f<2; f++) {
				for (int g=0; g<=n; g++) {
					dp[i][j][f][g] = LLONG_MAX;
				}
			}
		}
	}
	
	proc.push({pos[1], {{1, 1}, {0, pos[1] <= by[1]}}});
	proc.push({l-pos[n], {{n, n}, {1, (l - pos[n]) <= by[n]}}});
	
	int lr = 0;
	
	while (!proc.empty()) {
		
		auto x = proc.top(); proc.pop();
		
		int mtime = x.first;
		int lbound = x.second.first.first;
		int rbound = x.second.first.second;
		int curr = x.second.second.first;
		int taken = x.second.second.second;
		
		lr = max(lr, taken);
		
		if (dp[lbound][rbound][curr][taken] < mtime) continue;
		dp[lbound][rbound][curr][taken] = mtime;
		
		int at = (curr == 0 ? pos[lbound] : pos[rbound]);
		
		if (can(lbound, rbound)) continue;
		
		int before = prev(lbound);
		int dist = abs(at - pos[before]);
		proc.push({min(dist, l - dist) + mtime, {{before, rbound}, {0, taken + ((min(dist, l - dist) + mtime) <= by[before])}}});
		
		int after = next(rbound);
		dist = abs(at - pos[after]);
		proc.push({min(dist, l - dist) + mtime, {{lbound, after}, {1, taken + ((min(dist, l - dist) + mtime) <= by[after])}}});
		
	}
	
	cout << lr << endl;
	

}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75