递归系列-------------全排列递归解法

#include <stdio.h>

void permutation(char s[], int b, int e)
{
if( (0 <= b) && (b <= e) )
{
if( b == e )
{
printf("%s\n", s);
}
else
{
int i = 0;

for(i=b; i<=e; i++)
{
char c = s[b];
s[b] = s[i];
s[i] = c;

permutation(s, b+1, e);

c = s[b];
s[b] = s[i];
s[i] = c;
}
}
}
}

int main()
{
char s[] = "abcd";

permutation(s, 0, 3);
getchar();
return 0;
}