Stock Exchange

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
using namespace std;
int a[100005], num[100005];

int dichotomy(int len ,int n){
int left = 1,right = len;
int mid;
while(left <= right){
    mid = (right + left)/2;
    if(num[mid] == n ) return mid;
    else if(num[mid] > n) right = mid - 1;
    else if(num[mid] < n) left = mid + 1;//如果后面的数小于前面的书就把原来的给覆盖掉，如果后面数大于前面的数，就加一个，大多数情况是超出了while的条件出去的，跟mid关系不大.
      }
return left;
}
int main(){
int n;
while(~scanf("%d",&n)){
      for(int i = 1; i <= n; i++){
        scanf("%d", &a[i]);
      }
      num[1] = a[1];
      int len = 1;
      for(int i = 1; i <=   n; i++){
    int     j = dichotomy(len,a[i]);
        num[j] = a[i];
        if(j > len)
         len = j;//记录上升的个数
      }
    printf("%d\n", len);
        }
    return 0;

}