• Source 
    1. /**************************************************************
    2.     Problem: 1113
    3.     User: zrts
    4.     Language: C++
    5.     Result: Accepted
    6.     Time:1496 ms
    7.     Memory:1780 kb
    8. ****************************************************************/
    9.  
    10. #include<cstdio>
    11. #include<cstring>
    12. #include<algorithm>
    13. //by zrt
    14. //problem:
    15. using namespace std;
    16. typedef long long ll;
    17. const double eps(1e-10);
    18. int stk[250005],top;
    19. int main(){
    20.     #ifdef LOCAL
    21.     freopen("in.txt","r",stdin);
    22.     freopen("out.txt","w",stdout);
    23.     #endif
    24.     int n;
    25.     scanf("%d",&n);
    26.     int ans=0;
    27.     for(int i=0,x;i<n;i++){
    28.         scanf("%*d%d",&x);
    29.         while(top>0&&x<=stk[top-1]) {
    30.             top--,ans++;
    31.             if(stk[top]==x) ans--;
    32.         }
    33.         stk[top++]=x;
    34.     }
    35.     printf("%d\n",ans+top);
    36.     return 0;
    37. }