2020-09-13 木材加工

https://www.luogu.com.cn/problem/P2440

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <sstream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;

//template<typename DataType>
//DataType qmi(DataType m, int k)
//{
//    DataType res = 1, t = m;
//    while (k)
//    {
//        if (k&1) res = res * t;
//        t = t * t;
//        k >>= 1;
//    }
//    return res;
//}


int qmi(int m, int k)
{
    int res = 1, t = m;
    while (k)
    {
        if (k&1) res = res * t;
        t = t * t;
        k >>= 1;
    }
    return res;
}

int read(){
    int x = 0,f = 1;
    char c = getchar();
    while (c<'0'||c>'9') {
        if (c=='-') {
            f = -1;
        }
        c = getchar();
    }
    while (c>='0'&&c<='9') {
        x = x*10+c-'0';
        c = getchar();
    }
    return x*f;
}

#define fi(a,b) for(int i = a; i <= b; i++)
#define fj(a,b) for(int j = a; j >= b; j--)

struct priceAndCnt{
    int price,cnt;
};

void quickSort(priceAndCnt *a,int left,int right){
    int i,j;
    
    priceAndCnt temp,t;
    
    temp = a[(left+right)/2];//基准值
    
    i = left;
    j = right;
    
    while(i<=j){
        while (a[j].price > temp.price) {
            j--;
        }
        
        while (a[i].price < temp.price) {
            i++;
        }
        
        if (i<=j) {
            t = a[i];
            a[i] = a[j];
            a[j] = t;
            //继续下一步
            i++;
            j--;
        }
    }
    
    if(left<j)quickSort(a,left, j);//继续分治
    if(i<right)quickSort(a,i, right);//继续分治
}

long long n,k,ans,wood[100005],k1,flag,MAX = 100000001;

void test(long long mid){
    ans = 0;
    fi(1, n){
        ans += wood[i]/mid;
    }
    if(ans >= k) {
        flag = 0;
    } else if(ans < k) {
        flag = -1;
    }
}

int main()
{
    cin>>n;
    cin>>k;
    
    fi(1, n){
        wood[i] = read();
    }
    
    //cout<<MAX;
    if(MAX<=0){//如果连1cm长的小段都切不出来，输出”0”。
        cout<<0<<endl;
        return 0;
    }
    long long l = 0 ,r = MAX;
    while(l + 1 < r){
        long long mid = (l + r) / 2;
        test(mid);
        if(flag == -1){
            r = mid;
        } else if(flag == 0) {
            l = mid;
        }
    }
    cout<<l<<endl;
    return 0;
}
/*
3 7
232
124
456
============
114
*/