void perm(char *list, int i, int n){
int j,temp;
if(i == n){
for(j = 0; j < n; j++)
cout<<list[j];
cout<<" ";
}
else{
for(j = i; j < n; j++){
SWAP(list[i],list[j],temp);
perm(list,i+1,n);
SWAP(list[i],list[j],temp);
}
for(j = i; j < n; j++){
SWAP(list[i],list[j],temp); //將第j數字做為第一個
perm(list,i+1,n);
SWAP(list[i],list[j],temp); //將第j數字換回原來位置，準備用第j+1個做做為第一個
}
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建議你將函數修改成以下形式，自己觀察一下
-----------------------------------------------------------
void perm(char *list, int i, int n){
int j,temp;
for(j = 0; j < n; j++)
cout<<list[j]<<endl;
if(i == n){
for(j = 0; j < n; j++)
cout<<list[j];
cout<<" "<<i=n了<<" ";
}
else{
for(j = i; j < n; j++){
SWAP(list[i],list[j],temp);
perm(list,i+1,n);
SWAP(list[i],list[j],temp);
}
========================================================================================================
下面是完整的程序:C#
using System;
using System.Collections.Generic;
using System.Text;
namespace Test
{
class Program
{
static void Main(string[] args)
{
char[] list = {'a','b','c','d' };
perm(list, 0, 4);
Console.ReadLine();
}
static void perm(char[] list, int i, int n)
{
int j,temp;
if(i==n)
{
for(j=0;j<n;j++)
{
Console.Write(list[j]);
//Console.WriteLine();
}
}
else
{
for (j=i;j<n;j++)
{
swap(ref list[i],ref list[j]);
perm(list,i+1,n);
swap(ref list[i], ref list[j]);
}
}
}
static void swap(ref char a, ref char b)
{
char c = a;
a = b;
b = c;
}
}
}