示例1：C语言版

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
//随机产生规定个数的不重复数字
int findSame(int *arr, int in, int n);

int main() {
	//设置随机种子
	srand((int)time(0));
	int arr[40] = {0}, tmp, length = 0;

	while(length <= 39) {
		tmp = (40 * rand()) / RAND_MAX;
		//第一个下标数直接复制进数组
		if (length == 0)
			arr[length] = tmp;
		else {
			//第二个下标数开始，判断随机数是否在数组已经存在，存在的话跳过，不存在就复制进数组
			if (findSame(arr, tmp, length) == 1)
				continue;
			else 
				arr[length] = tmp;
		}
		length++;
	}
		
	for (int i = 0; i < 40; i++)
		printf("%d ", arr[i]);
	return 0;
}

int findSame(int *arr, int in, int n) {
	for (int i = 0; i < n; i++) {
		if (arr[i] == in)
			return 1;
	}
	return 0;
}

import java.util.*;
//打印10个不重复的随机数字1~10
public class NoRepeatNumber {

	public static void main(String[] args) {
		Random random = new Random();
		int [] nums = new int[10];
		List<Integer> mylist = new ArrayList<Integer>();
		int n = 10, temp, i = 0;
		
		while(mylist.size() < n){
			temp = random.nextInt(n) + 1;
			if (!mylist.contains(temp)) {
				mylist.add(temp);
				nums[i] = temp;
				System.out.print(nums[i] + " ");
			}		
		}
	}

}

C语言、Java两种方式下的——规定范围内不重复随机数