好条形图510hist.cpp

设计一个算法

#include<iostream>
#include<fstream>
#include"time.h"
using namespace std;
inline void Swap(int &a,int &b)
{
	int temp=a;
	a=b;
	b=temp;
}
int Patition(int a[],int p,int r)
{
	int i=p,
		j=r+1;
	int x=a[p];
	while(true)
	{
		while(a[++i]<x);
		while(a[--j]>x);
		if(i>=j)break;
		Swap(a[i],a[j]);
	}
	a[p]=a[j];
	a[j]=x;
	return j;
}

void QuickSort(int a[],int p,int r)
	{
		if(p<r)
		{
			int q=Patition(a,p,r);
			QuickSort(a,p,q-1);
			QuickSort(a,q+1,r);
		}
	}
clock_t start,finish;
void main()
{
	start=clock();
	ifstream in("input.txt");
	if(in.fail())
	{
		cout<<"the input.txt is not exist!";
		exit(1);
	}
	ofstream out("output.txt");
	int n;
	in>>n;
	int *a=new int[n];
	int i;
	for(i=0;i<n;i++)
		in>>a[i];
    QuickSort(a,0,n-1);
	int count=1;
	for(i=0;i<n;i++)
	{
		if(a[i]==a[i+1])
		{
			count++;
			continue;
		}
		out<<a[i-count+1]<<" "<<count<<endl;
		count=1;
	}
	delete[]a;
	finish=clock();
	cout<<finish-start<<endl;
}