Codeforces 472B - Design Tutorial: Learn from Life（模拟）

题意

有一个载重量为K的电梯，有N个人，每个人都有想去的地方，求电梯送他们到站的最少时间。

思路

一开始我想从低到高来载，发现不好搞。

换个思路，先运最高的人，如果还有空的话顺路载一下低一点的人。

不过还是感觉我的思路很low。。。

代码

#include <cstdio>
#include <stack>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <functional>
#include <cstring>
#include <algorithm>
#include <cctype>
#include <ctime>
#include <cstdlib>
#include <fstream>
#include <string>
#include <sstream>
#include <map>
#include <cmath>
#define LL long long
#define lowbit(x) ((x) & (-x))
#define MP(a, b) make_pair(a, b)
#define MS(arr, num) memset(arr, num, sizeof(arr))
#define PB push_back
#define F first
#define S second
#define ROP freopen("input.txt", "r", stdin);
#define BitCount(x) __builtin_popcount(x)
const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
using namespace std;
const int MAXN = 2000 + 5;
const int MOD = 20071027;
typedef pair<int, int> pii;
typedef vector<int>::iterator viti;
typedef vector<pii>::iterator vitii;
int num[MAXN];
int main()
{
    //ROP;
    int n, cap, i, j;
    int tmp;
    scanf("%d%d", &n, &cap);
    for (i = 0; i < n; i++)
    {
        scanf("%d", &tmp);
        num[tmp]++;
    }
    int cur = cap, ans = 0;
    for (i = 2000; i >= 2; i--)
    {
        while (num[i])
        {
            if (cur != cap)
            {
                if (num[i] >= cur)
                {
                    num[i] -= cur;
                    cur = 0;
                }
                else
                {
                    cur -= num[i];
                    num[i] = 0;
                }
                if (cur == 0) cur = cap;
                continue;
            }
            else if (num[i] >= cur)
            {
                num[i] -= cur;
                cur = 0;
                ans += ((i - 1) << 1);
            }
            else
            {
                ans += ((i - 1) << 1);
                cur -= num[i];
                num[i] = 0;
            }
            if (cur == 0) cur = cap;
        }
    }
    printf("%d\n", ans);
    return 0;
}