[数据结构]全排列

例如 123

123

132

213

231

312

321

#include <stdio.h>  

int n = 0;  

void swap(int *a, int *b) 
{     
    int m;     
    m = *a;     
    *a = *b;     
    *b = m; 
}  
void perm(int list[], int k, int m) 
{     
    int i;     
    if(k > m)     
    {          
        for(i = 0; i <= m; i++)             
            printf("%d ", list[i]);         
        printf("\n");         
        n++;     
    }     
    else     
    {         
        for(i = k; i <= m; i++)         
        {             
            swap(&list[k], &list[i]);             
            perm(list, k + 1, m);             
            swap(&list[k], &list[i]);         
        }     
    } 
} 
int main() 
{     
    int list[] = {1, 2, 3, 4, 5};     
    perm(list, 0, 4);     
    printf("total:%d\n", n);     
    return 0; 
}