<div class="post_brief"><p>
又搬blog。发现这里可以自定义css之后就果断了。</p>

 

写道水题试试。set的应用。然后还写丑WA了两次，我没救了。

 

代码高亮是坏了吗？不要吓我。

 

决定直接用oj7的代码版了，没有高亮就算了。

#include <cstdio>
#include <algorithm>
#include <set>

using namespace std;


typedef multiset <int> rb_tree;
typedef rb_tree :: iterator rb_node;
typedef pair <int, int> cow;


const int maxn = 50009;


int n, d, x[maxn], a[maxn], r[maxn];
cow c[maxn];
rb_tree t;


int main() {
#ifndef ONLINE_JUDGE
freopen(“in.txt”, “r”, stdin);
#endif


scanf("%d%d", &amp;n, &amp;d);
for (int i = 1; i &lt;= n; ++ i) {
	scanf("%d%d", x + i, a + i);
	c[i] = cow(x[i], a[i]);
	r[i] = 0;
}
sort(c + 1, c + n + 1);
for (int i = 1; i &lt;= n; ++ i) {
	x[i] = c[i]. first;
	a[i] = c[i]. second;
}
for (int i = 1, j = 1; i &lt;= n; ++ i) {
	while (x[i] - x[j] &gt; d) {
		t. erase(t. find(a[j]));
		++ j;
	}
	if (t. lower_bound(a[i] &lt;&lt; 1) != t. end())
		++ r[i];
	t. insert(a[i]);
}
t. clear();
int ans(0);
for (int i = n, j = n; i; -- i) {
	while (x[j] - x[i] &gt; d) {
		t. erase(t. find(a[j]));
		-- j;
	}
	if (t. lower_bound(a[i] &lt;&lt; 1) != t. end())
		++ r[i];
	if (r[i] == 2)
		++ ans;
	t. insert(a[i]);
}
printf("%d\n", ans);



}