大家看看，给点意见哦
//~~~~~~~~~~全排列~~~~~~~~~~~~~~~~//
#include<iostream.h>
#include<math.h>
#include<fstream.h>
#include<stdlib.h>
int search_num(int *a,int t)
{
for(int j=1;j<=t;j++)
{
for(int i=0;i<t;i++)
if(j==a[i]) break;
if(i==t) return 0;
}
return 1;
}
int yes(int k,int t)
{
int m=0;
int a[20];//这个数组的大小决定排序字符数的最大个数
for(int j=k;j!=0;j=j/10)
{
a[m++]=j%10;
}
if(search_num(a,t)) return 1;
return 0;
}

int main()
{
int yes(int k,int t);
int search_num(int *a,int t);

int N;
cout<<"输入你想排序的字符数: ";
cin>>N;
char *b=new char[N+1];
cout<<"输入字符 :";
for(int x=0;x<N;x++)
cin>>b[x];
b[N]='\0';
int num1=0;
int num2=0;
for(int i=1;i<=N;i++)
{
num1+=i*(int)pow(10,i-1);
}
for(i=N;i>=1;i--)
{
num2+=i*(int)pow(10,N-i);
}
int k=0;
fstream outFile;
outFile.open("file1.txt",ios::out);
if(!outFile)
{
cout<<"file1.txt can't open.\n";
abort();
}
outFile<<"以下为输入字符的全排列 : ("<<b<<")"<<endl;

for(int j=0;i<num1;j++)
{
i=num2+9*j;
if(yes(i,N))
{
int sd=10;
int asd=i;
for(int al=asd%sd;asd!=0;al=asd%sd)
{
outFile<<b[al-1];
asd=asd/sd;
}
outFile<<" ";
k++;
if(k%10==0) outFile<<endl;
}
}
outFile<<"~~~~~~输入字符的全排列个数为:~~~~~~~~"<<k;
delete []b;

return 0;
}