Submission #1091986

#	Time	Username	Problem	Language	Result	Execution time	Memory
1091986		thangdz2k7	Sparklers (JOI17_sparklers)	C++17	0 / 100	2 ms	1372 KiB

sparklers

// author : thembululquaUwU
// 3.9.2024

#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define fi first
#define se second
#define endl '\n'

using namespace std;
using ll = long long;
using ii = pair <int, int>;
using vi = vector <int>;

const int N = 1e3 + 5;
const int mod = 1e9 + 7;

void maxl(auto &a, auto b) {a = max(a, b);}
void minl(auto &a, auto b) {a = min(a, b);}

int n, k, t, x[N];

bool dp[N][N];

bool check(ll s) {
	memset(dp, 0, sizeof dp);
	dp[k][k] = 1;
	for (int len = 2; len <= n; ++ len) {
		for (int l = 1; l <= n; ++ l) {
			int r = l + len - 1;
			if (r > n) {
				break;
			}
			dp[l][r] = ((dp[l + 1][r] || dp[l][r - 1]) && (x[r] - x[l]) <= 2 * s * (r - l) * t);
		}
	}
	return dp[1][n];
}

void solve(){
    cin >> n >> k >> t;
    for (int i = 1; i <= n; ++ i) cin >> x[i];
    int lo = 1, hi = x[n] / t + 1, ans = hi;
    while (lo <= hi){
        int mid = lo + hi >> 1;
        if (check(mid)) ans = mid, hi = mid - 1;
        else lo = mid + 1;
    }
    cout << ans;
}

signed main(){
    if (fopen("pqh.inp", "r")){
        freopen("pqh.inp", "r", stdin);
        freopen("pqh.out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int t = 1; // cin >> t;
    while (t --) solve();
    return 0;
}

Compilation message (stderr)

sparklers.cpp:19:11: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   19 | void maxl(auto &a, auto b) {a = max(a, b);}
      |           ^~~~
sparklers.cpp:19:20: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   19 | void maxl(auto &a, auto b) {a = max(a, b);}
      |                    ^~~~
sparklers.cpp:20:11: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   20 | void minl(auto &a, auto b) {a = min(a, b);}
      |           ^~~~
sparklers.cpp:20:20: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   20 | void minl(auto &a, auto b) {a = min(a, b);}
      |                    ^~~~
sparklers.cpp: In function 'void solve()':
sparklers.cpp:46:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   46 |         int mid = lo + hi >> 1;
      |                   ~~~^~~~
sparklers.cpp: In function 'int main()':
sparklers.cpp:55:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         freopen("pqh.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:56:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         freopen("pqh.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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