第一维排序 第二维LIS

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

int dp[100010];
int p[100010];

struct node
{
	int x, y, id;
}a[100010];


bool cmp(node a, node b)
{
	if(a.x != b.x)
		return a.x < b.x;
	return a.y > b.y;
}

void print(int x)
{
	if(p[x] == -1)
	{
		printf("%d", a[x].id);
		return;
	}
	print(p[x]);
	printf(" %d", a[x].id);
}
int main()
{
	int n;
	while(scanf("%d", &n) != EOF)
	{
		memset(dp, -1, sizeof(dp));
		memset(p, -1, sizeof(p));
		
		for(int i = 1; i <= n; i++)
		{
			scanf("%d %d", &a[i].x, &a[i].y);
			a[i].id = i;
		}
		sort(a+1, a+n+1, cmp);
		dp[1] = 1;
		int len = 1;
		for(int i = 2; i <= n; i++)
		{
			int l = 1, r = len;
			while(l <= r)
			{
				int m = (l + r) >> 1;
				if(a[dp[m]].y < a[i].y)
					l = m+1;
				else
					r = m-1;
			}
			dp[l] = i;
			p[i] = dp[l-1];
			if(l > len)
				len = l;

		}
		//sort(dp+1, dp+len+1);
		printf("%d\n", len);
		print(dp[len]);
		puts("");
	}
	return 0;
}

SGU 199. Beautiful People 二维LIS