Submission #551049

#	Time	Username	Problem	Language	Result	Execution time	Memory
551049		LucaDantas	Sparklers (JOI17_sparklers)	C++17	50 / 100	50 ms	4416 KiB

sparklers

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

constexpr int maxn = 1010, inf = 0x3f3f3f3f;

int x[maxn], n, k, T, v;

int dp[maxn][maxn];

void solve(int l, int r) {
    if(dp[l][r]) return;
    dp[l][r] = 1;
    if(l && (x[r] - x[l-1]) <= 1ll * 2 * v * T * (r-l+1))
        solve(l-1, r);
    if(r < n-1 && (x[r+1] - x[l]) <= 1ll * 2 * v * T * (r-l+1))
        solve(l, r+1);
}

int main() {
    scanf("%d %d %d", &n, &k, &T); --k; // 0-indexed
    for(int i = 0; i < n; i++)
        scanf("%d", x+i);

    int l = 0, r = inf, ans = -1;
    while(l <= r) {
        int m = (l+r) >> 1;
        v = m;
        memset(dp, 0, sizeof dp);
        solve(k, k);
        if(dp[0][n-1])
            r = m-1, ans = m;
        else
            l = m+1;
    }

    printf("%d\n", ans);
}

Compilation message (stderr)

sparklers.cpp: In function 'int main()':
sparklers.cpp:20:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     scanf("%d %d %d", &n, &k, &T); --k; // 0-indexed
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:22:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |         scanf("%d", x+i);
      |         ~~~~~^~~~~~~~~~~

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