Submission #1034389

#	Time	Username	Problem	Language	Result	Execution time	Memory
1034389		tvladm2009	Sparklers (JOI17_sparklers)	C++17	0 / 100	0 ms	468 KiB

sparklers

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
 
const int N = 1e3 + 5;
 
ll n, k, t;
ll x[N];
bool dp[N][N];
 
bool check(__int128 v) {
    printf("v=%d\n", (int)v);
    memset(dp, 0, sizeof(dp));
    dp[k][k] = 1;
    for (int l = k; l >= 1; l--) {
        for (int r = k; r <= n; r++) {
            if (dp[l][r]) {
              if (r < n && x[r + 1] - x[l] <= 2 * v * (r - l + 1) * t) dp[l][r + 1] = 1;
              if (l > 1 && x[r] - x[l - 1] <= 2 * v * (r - l + 1) * t) dp[l - 1][r] = 1;
            }
            printf("%d ", dp[l][r]);
        }
        printf("\n");
    }
    return dp[1][n];
}
 
bool check2(__int128 v) {
  int l = k;
  int r = k;
  for (int i = 0; i < n; i++) {
    while (r < n && x[r + 1] - x[l] <= 2 * v * (r - l + 1) * t)
      r++;
    while (l > 1 && x[r] - x[l - 1] <= 2 * v * (r - l + 1) * t)
      l--;
  }
  return l == 1 && r == n;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> k >> t;
    for (int i = 1; i <= n; ++i) cin >> x[i];
    
    ll l = 0, r = 1e9, sol = -1;
    while (l <= r) {
        ll m = (l + r) / 2;
        if (check2(m)) {
            sol = m;
            r = m - 1;
        } else {
            l = m + 1;
        }
    }
    cout << sol << "\n";
    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50