递归 全排列

void swapChar(char str[], int i, int j)
{
int t = str[j];
str[j] = str[i];
str[i] = t;
}

void showString(char str[], int len)
{
if (len == 0)
{
cout << str-4 << endl;
return;
}

for (int i = 0; i < len; i++)
{
swapChar(str, 0, i);
showString(str + 1, len - 1);
swapChar(str, 0, i);
}
}

int main()
{
/*int a[] = { 1, 2, 7, 4, 6, 6, 7, 8, 10, 4 };
for (int i = 0; i < 10; i++)
{
cout << random_select(a, 0, 9, i+1) << endl;
}*/
char str[] = "abcd";
showString(str, 4);
return 0;
}