数据结构与算法----5.1 全排列

[c++]代码库

#include <iostream>
#include <string>
using namespace std;

bool ok (char a[], int k, int i)
{
	for ( int t=k ; t<i; t++)
		if (a[t] == a[i] ) return false;
		return true ;
}

void perm (char a[], int k, int n)
{
	int i;	 char c; 
	if (k==n) 	 
	{
		for (i=0;i<n;i++) cout<<a[i];
		cout<<endl; return;
	}	
	
	for (i=k ; i<n ; i++) if (ok (a, k,i ) ) 
	{
		c=a[i];a[i]=a[k];a[k]=c;
		perm (a, k+1, n);
		c=a[i];a[i]=a[k];a[k]=c;
	}
	
}
void perm (char a[])
{
	perm (a,0, strlen(a)); 
}
int main()
{

	char p[]="1122";
	int j=strlen(p);
	cout<<"数据元素：";
	for (int i=0;i<j;i++)
	{
		if(i!=j-1)
		cout<<p[i]<<",";
		else
	    cout<<p[i];
	}
	cout<<endl<<"全排列为："<<endl;	
	perm(p);
	return 0;
}