codeforce 589B枚举

2017-08-25 12:00:53

writer：pprp

很简单的枚举，但是我调试了很长时间，出现各种各样的问题

/*
theme:cf 589B
writer:pprp
declare:枚举
date:2017/8/25
*/

#include <bits/stdc++.h>

using namespace std;
const int N = 4040;
typedef long long ll;
ll ans = -1, record_w = -1, record_h = -1;

class rect
{
public:
    int w;
    int h;

    bool operator <(const rect & r2)
    {
        return w < r2.w;
    }

};

rect rec[N];

int main()
{
    int n;
    scanf("%d",&n);

    //input section
    for(int i = 0 ; i < n ; i++)
    {
        scanf("%d%d",&rec[i].w, &rec[i].h);
        //w is bigger than h
        if(rec[i].w > rec[i].h)    //w > h??
            swap(rec[i].w,rec[i].h);
    }
    //sort the w
    sort(rec,rec + n);

    //define a vector to store the height
    vector<int> hh;

    //从小到大枚举w的长度
    for(int i = 0 ; i < n ; i++)
    {
        hh.clear();
        //将宽度高于w的对象的h储存在vector中
        for(int j = i  ; j < n ; j++)
            hh.push_back(rec[j].h);

        //对高度进行排序
        sort(hh.begin(), hh.end());

        //记录当前高度
        int len = hh.size();

        //枚举当前w的情况下，采用不同的h的最佳解
        for(int j = 0 ; j < hh.size() ; j++, len--)
        {
            ll cmp = (ll)rec[i].w * hh[j] * len;    //wrong before: (ll)(rec[i].w * hh[j] * len) 这样就会越界
            if(cmp > ans)
            {
                ans = cmp;
                record_h = hh[j];
                record_w = rec[i].w;
            }
        }
    }
    cout << ans << endl;
    cout << record_w << " " << record_h << endl;

    return 0;
}