Los greedy algorithm topic souvenir packet Valley P1094

Los greedy algorithm topic souvenir packet Valley P1094

topic:

New Year's Day approaching, students will be responsible for Lele souvenir New Year's party of issuance of work. So the students to the party souvenir value obtained is relatively balanced, he wanted to buy souvenirs are grouped according to price, but only up each consisting of two memorabilia and souvenirs in each price can not exceed a given integer. To ensure that all souvenirs finished in the shortest possible time, Lele desired minimum number of packets.

Your task is to write a program to find the minimum number of packets all packets program one of the least number of packets output.

Resolution:

This question

And P1090

look alike

But one is

Minimum

Is a minimum number of additions

There is a certain limit

So different

Here is the analysis:

This question

First, the first sort

With minimal

And the largest ratio

A ratio of a down

Find the words

Since count on a pile

Otherwise put

That number removed

Very simple

code show as below:

#include<bits/stdc++.h>
#include<iostream>
#include<cstdlib>
#include<cstdio>
using namespace std;
int n,a[30001],m,d,sum=0;
int main()
{
    freopen("P1094_6.in","r",stdin);
    freopen("P1094_6.out","w",stdout);
    bool flag=true,flag2[30001];
    memset(flag2,0,sizeof(flag2));
    cin>>m;
    cin>>n;
    for(int i=1;i<=n;i++)
    cin>>a[i];
    sort(a+1,a+n+1);
    for(int i=1;i<=n;i++)
    {
        flag=true;
        for(int j=n;j>i;j--)
        {
            if(a[i]+a[j]<=m&&flag2[i]==0&&flag2[j]==0)
            {
                flag2[i]=1;
                flag2[j]=1;
                //cout<<a[i]<<" "<<a[j]<<endl;
                flag=false;
                d=j;
                break;
            }
        }
        if(flag==false)
        {
            for(int j=d;j<=n-1;j++)
            a[j]=a[j+1];
            n--;
        }
        //else cout<<a[i]<<endl;;
        sum++;
    }
    cout<<sum<<endl;
    return 0;
}

Bye! ! ! ! ! ! !