【51Nod】1279 - 扔盘子（二分）

#include <cstdio>
#include <cstring>
#include <queue>
#include <cmath>
#include <stack>
#include <vector>
#include <algorithm>
using namespace std;
#define INF 0x3f3f3f3f
#define CLR(a,b) memset(a,b,sizeof(a))
#define PI acos(-1.0)
#define LL long long
int main()
{
    int n,m;
    int t;
    int minn = 1e9 + 7; 
    scanf ("%d %d",&n,&m);
    vector<int> v;
    for (int i = 0 ; i < n ;i++)
    {
        scanf ("%d",&t);
        minn = min(minn,t);
        v.push_back(minn);
    }
    int endd = v.size();
    int l,r,mid;
    int ans = 0;
    for (int i = 0 ; i < m ; i++)
    {
        scanf ("%d",&t);
        l = 0;
        r = endd;
        while (r >= l)
        {
            mid = (l + r) >> 1;
            if (r == l && r == endd)
            {
                l = endd;
                break;
            }
            if (t <= v[mid])
                l = mid + 1;
            else
                r = mid - 1;
        }
        endd = l - 1;
        if (endd == -1)     //判断是否没有位置 
            continue;
        ans++;
    }
    printf ("%d\n",ans);
    return 0;
}