题目1：40人，随机分成十组，每组四人，姓名用序号代替。

#include <stdio.h>#include <time.h>void swap(int *a, int i, int j){int tmp = a[i];a[i] = a[j];a[j] = tmp;}void printA(int *a, int len){int i;for (i = 0; i < len; i ++){if (i % 4 == 0)printf ("\n");printf ("%4d", a[len - i-1]);}printf ("\n");}int main(){srand ((unsigned int)time(NULL)); int a[40];int i;int len = 40;for (i = 0; i < 40; i++){a[i] = i;}for (i = len-1; i > 0; i--){int index = rand() % (i+1);swap (a, index, i);}printA(a, len);return 0;}