Submission #237566

#	Time	Username	Problem	Language	Result	Execution time	Memory
237566		jingyanyu	Watching (JOI13_watching)	C++17	100 / 100	226 ms	16124 KiB

watching

#include <bits/stdc++.h>
using namespace std;
const int N = 2005;
int a[N], dp[N][N];
int main() {
    int n, p, q;
    scanf("%d%d%d", &n, &p, &q);
    for (int i = 1; i <= n; i++) {
        scanf("%d", a + i);
    }
    sort(a + 1, a + n + 1);
    int l = 1, r = 1000000000, res;
    while(r - l >= 0) {
        int mid = (l + r) >> 1;
        dp[0][0] = 0;
        for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)dp[i][j]=n+1;
        for (int i = 1; i <= n; i++) {
            int pp = 1, pq = 1;
            for (int j = i; j >= 1; j--) {
                if (a[i] - a[j] + 1 <= mid) pp = j;
                if (a[i] - a[j] + 1 <= 2*mid) pq = j;
            }
            dp[i][0] = dp[pq - 1][0] + 1;
            for (int j = 1; j <= min(i, p); j++) {
                dp[i][j] = min(dp[pp - 1][j - 1], dp[pq - 1][j] + 1);
            }
        }
        int mn = dp[n][0];
        for (int i = 1; i <= n; i++) {
            mn = min(mn, dp[n][i]);
        }
        if (mn <= q) {
            r = mid - 1;
            res = mid;
        } else {
            l = mid + 1;
        }
    }
    printf("%d\n", res);
    return 0;
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:7:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &n, &p, &q);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
watching.cpp:9:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", a + i);
         ~~~~~^~~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50