ACM篇：POJ 3903--Stock Exchange

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>

using namespace std;

const int MAXN = 100000;
int arr[MAXN+2];
int ans[MAXN+2];

int _bin(int *arr, int lo, int hi, int k)
{
while (lo < hi)
{
int mid = (lo+hi)>>1;
if (arr[mid] < k)
lo = mid + 1;
else
hi = mid;
}
return lo;
}
int main()
{
int n;
int top;

while (scanf("%d", &n) != EOF)
{

for (int i = 1; i <= n; i++) scanf("%d", arr+i);
ans[top=1] = arr[1];
for (int i = 2; i <= n; i++)
{
if (arr[i] > ans[top]) ans[++top] = arr[i];
else if (arr[i] < ans[top])
{
int index = _bin(ans, 1, top, arr[i]);
ans[index] = arr[i];
}
}

printf("%d\n", top);
}
return 0;
}