洗牌数组内容
此算法将读取一个数组并随机打乱数组内容。这将生成数组元素的随机排列。
为了解决这个问题,我们将从最后索引开始,随机产生数组中的一个索引并交换元素。
输入和输出
Input: An array of integers: {1, 2, 3, 4, 5, 6, 7, 8} Output: Shuffle of array contents: 3 4 7 2 6 1 5 8 (Output may differ for next run)
算法
randomArr(array, n)
输入:数组、元素数量。
输出:打乱数组内容。
Begin for i := n – 1 down to 1, do j := random number from 0 to i swap arr[i] and arr[j] done End
示例
#include <iostream> #include<cstdlib> #include <ctime> using namespace std; void display(int array[], int n) { for (int i = 0; i < n; i++) cout << array[i] << " "; } void randomArr ( int arr[], int n ) { //generate random array element srand (time(NULL)); //use time to get different seed value to start for (int i = n-1; i > 0; i--) { int j = rand() % (i+1); //randomly choose an index from 0 to i swap(arr[i], arr[j]); //swap current element with element placed in jth location } } int main() { int arr[] = {1, 2, 3, 4, 5, 6, 7, 8}; int n = 8; randomArr(arr, n); display(arr, n); }
输出
4 7 8 2 6 3 5 1
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