洗牌陣列內容
此演算法將採用一個數組並洗牌陣列的內容。它將生成陣列元素的隨機排列。
要解決此問題,我們將從最後一個索引開始交換元素,隨機生成陣列中的一個索引。
輸入和輸出
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)
演算法
randomArr(array, n)
輸入:陣列、元素數量。
輸出:洗牌陣列內容。
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); }
輸出
4 7 8 2 6 3 5 1
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