生成字符串的重排集，考虑有重复的字符

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

char str[100];
char resultstr[100];
int visit[100];

void dfs( int cur , int len)
{
    if( cur == len )
    {
        printf("%s \n", resultstr );
    }
    int pre = -1;
    for( int i = 0 ; i < len ; i++ )
    {
        if( !visit[i] )
        {
            if( pre == -1  || str[pre] != str[i] )
            {
                pre = i;
                resultstr[cur] = str[i] ;
                visit[i] = true;
                dfs( cur + 1 , len );
                visit[i] = false;
            }
            else
                continue;
        }
        else
            continue;
    }
}

void sovle()
{
    int len = strlen( str );
    memset( resultstr , 0 , sizeof( resultstr ) );
    memset( visit  , 0  , sizeof( visit ) );
    printf("==============================\n");
    dfs( 0 , len );
    printf("==============================\n\n");
}

bool cmp ( const  char &a , const  char &b)
{
    return a < b ;
}

int main()
{
    memset( str , 0 ,sizeof( str ) );
    while( ~scanf("%s",str ) )
    {
        sort( str , str+strlen(str) );
        sovle();
    }
    return 0;
}