HDU - 4521 小明系列问题――小明序列 (存在间隔的LIS)

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思路：我觉得挺费神的一道题，与以往的O(nlogn)LIS不一样，每次我们处理到第i个元素的时候，才去处理第i-d的数，判断是否放进队列里面
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
const int maxn = 100005;
const int inf = 0x3f3f3f3f;

int n, d;
int seq[maxn], num[maxn];
int dp[maxn];

int main() {
	while (scanf("%d%d", &n, &d) != EOF) {
		for (int i = 1; i <= n; i++)
			scanf("%d", &seq[i]);
		
		for (int i = 0; i <= n+1; i++)
			num[i] = inf;
		memset(dp, 0, sizeof(dp));

		int ans = 0;
		for (int i = 1; i <= n; i++) {
			int k = lower_bound(num, num+n, seq[i]) - num;
			dp[i] = k;
			ans = max(ans, dp[i]+1);
			int j = i - d;
			if (j > 0) {
				int tmp = dp[j];
				num[tmp] = min(num[tmp], seq[j]);
			}
		}
		
		printf("%d\n", ans);
	}
	return 0;
}