排列问题

#include<stdio.h>#define n 3void perm(int a[],int begin,int end){int t;if(begin == end){for(int i = 0;i < n;i ++)printf("%d ",a[i]);putchar('\n');}else{for(int i = begin;i < n;i ++){t = a[begin];a[begin] = a[i];a[i] = t;perm(a,begin + 1,end);t = a[begin];a[begin] = a[i];a[i] = t;}}}int main(){int a[n] = {1,2,3};perm(a,0,2);return 0;}