#include <stdio.h>#include <stdlib.h>#include <time.h>int d[6];int i,n,a,b,t;int c,j;void main() { srand(time(NULL)); printf("shuffle 0..n-1 demo\n"); for (n=1;n<=5;n++) {/* 测试1～5个元素 */ printf("_____n=%d_____\n",n); j=1; for (c=1;c<=n;c++) j=j*c;/* j为n! */ j*=n*2; for (c=1;c<=j;c++) {/* 测试n*2*n!次 */ for (i=0;i<n;i++) d[i]=i;/* 填写0～n-1 */ for (i=n;i>0;i--) {/* 打乱0～n-1 */ a=i-1;b=rand()%i; if (a!=b) {t=d[a];d[a]=d[b];d[b]=t;} } printf("%04d:",c); for (i=0;i<n;i++) printf("%d",d[i]);