bzoj1113

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=1113

题解：单调栈

代码：

 1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdio>
 4 #include<algorithm>
 5 #define maxn 250005
 6 using namespace std;
 7 int n;
 8 int a[maxn],b[maxn],z[maxn];
 9 int main()
10 {
11     scanf("%d\n",&n);
12     int mmax=0,top=0,ans=0;
13     for (int i=1; i<=n; i++) scanf("%d%d",&a[i],&b[i]),mmax=max(mmax,b[i]);
14     z[0]=0;
15     for (int i=1; i<=n; i++)
16     {
17         while (z[top]>b[i]) top--;
18         if (z[top]<b[i]) ans++;
19         z[++top]=b[i];
20     }
21     printf("%d\n",ans);
22 }