[BZOJ 1113][Poi2008]海报PLA：单调栈

/*
User:Small
Language:C++
Problem No.:1113
*/
#include<bits/stdc++.h>
#define ll long long
#define inf 999999999
using namespace std;
const int M=25e4+5;
int t,x,ans,n,tp,s[M];
int main(){
freopen("data.in","r",stdin);//
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d%d",&t,&x);
while(tp&&x<=s[tp]){
ans+=(x==s[tp]);
tp--;
}
s[++tp]=x;
}
printf("%d\n",n-ans);
return 0;
}