Project Euler：Problem 24 Lexicographic permutations

标签：c++   project euler   

A permutation is an ordered arrangement of objects. For example, 3124 is one possible permutation of the digits 1, 2, 3 and 4. If all of the permutations are listed numerically or alphabetically, we call it lexicographic order. The lexicographic permutations of 0, 1 and 2 are:

012   021   102   120   201   210

What is the millionth lexicographic permutation of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9?

求0~9第1000000的排列是什么。

#include <iostream>
using namespace std;

int list[11] = { 0,0, 1, 2 ,3,4,5,6,7,8,9};
int main()
{
	int n = 10;
	for (int tt = 1; tt <= 1000000-1; tt++)
	{
		int point;
		for (int i = n; i >= 1; i--)
		{
			if (list[i] < list[i - 1])
				continue;
			else
			{
				point = i - 1;
				break;
			}
		}

		if (list[point] < list[n])
			swap(list[point], list[n]);
		else
		{
			for (int i = point + 1; i <= n - 1; i++)
			{
				if (list[point] < list[i] && list[point]>list[i + 1])
					swap(list[point], list[i]);
			}
		}
		int kk = n;
		for (int i = point + 1; i <= kk; i++, kk--)
		{
			int temp;
			temp = list[i];
			list[i] = list[kk];
			list[kk] = temp;
		}
		
	}
	for (int i = 1; i <= n; i++)
			cout << list[i] << " ";
		cout << endl;
	
	system("pause");
	return 0;
}

Project Euler：Problem 24 Lexicographic permutations

标签：c++   project euler   

原文地址：http://blog.csdn.net/youb11/article/details/46317469