98: 模拟赛-神光 dp

$code$

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

int n, p, q, a[], l = , r = , ans = ;
int dp[][], P[], Q[];

bool check(int L) {
    memset(dp, , sizeof(dp));
    memset(P, , sizeof(P));
    memset(Q, , sizeof(Q));
    for (int i = ; i <= n; i++)
        for (int j = i; j <= n; j++) {
            if (a[j] - a[i] + <= L) P[i] = j;
            if (a[j] - a[i] + <= *L) Q[i] = j;
        }
    P[n+] = Q[n+] = n;
    for (int i = ; i <= p; i++)
        for (int j = ; j <= q; j++) {
            if (i > ) dp[i][j] = max(dp[i][j], P[dp[i-][j] + ]);
            if (j > ) dp[i][j] = max(dp[i][j], Q[dp[i][j-] + ]);
        }
    return dp[p][q] == n;
}

int main() {
    scanf("%d%d%d", &n, &p, &q);
    for (int i = ; i <= n; i++)
        scanf("%d", &a[i]);
    sort(a + , a +  + n);
    a[] = ;
    r = a[n] - a[] + ;
    if (p + q >= n) {
        printf("1\n");
        return ;
    }
    while (l <= r) {
        int mid = (l+r) / ;
        if (check(mid)) ans = mid, r = mid -;
        else l = mid + ;
    }
    printf("%d\n", ans);
    return ;
}