# 在數組中找到第一個，第二個和第三個最小元素 > 原文： [https://www.geeksforgeeks.org/find-the-first-second-and-third-minimum-elements-in-an-array/](https://www.geeksforgeeks.org/find-the-first-second-and-third-minimum-elements-in-an-array/) 在`O(n)`中找到數組中的第一，第二和第三最小元素。 例子： ``` Input : 9 4 12 6 Output : First min = 4 Second min = 6 Third min = 9 Input : 4 9 1 32 12 Output : First min = 1 Second min = 4 Third min = 9 ``` **第一種方法**：首先，我們可以使用常規方法對數組進行排序，然后打印數組的第一，第二和第三元素。 該解決方案的時間復雜度為`O(N log N)`。 **第二種方法**：此解決方案的時間復雜度為`O(n)`。 算法- ``` First take an element then if array[index] < Firstelement Thirdelement = Secondelement Secondelement = Firstelement Firstelement = array[index] else if array[index] < Secondelement Thirdelement = Secondelement Secondelement = array[index] else if array[index] < Thirdelement Thirdelement = array[index] then print all the element ``` ## C++ ```cpp // CPP program to find the first, second // and third minimum element in an array #include<bits/stdc++.h> #define MAX 100000 using namespace std; int Print3Smallest(int array[], int n) { ????int firstmin = MAX, secmin = MAX, thirdmin = MAX; ????for (int i = 0; i < n; i++) ????{ ????????/* Check if current element is less than ???????????firstmin, then update first, second and ???????????third */ ????????if (array[i] < firstmin) ????????{ ????????????thirdmin = secmin; ????????????secmin = firstmin; ????????????firstmin = array[i]; ????????} ????????/* Check if current element is less than ????????secmin then update second and third */ ????????else if (array[i] < secmin) ????????{ ????????????thirdmin = secmin; ????????????secmin = array[i]; ????????} ????????/* Check if current element is less than ????????then update third */ ????????else if (array[i] < thirdmin) ????????????thirdmin = array[i]; ????} ????cout << "First min = " << firstmin << "\n"; ????cout << "Second min = " << secmin << "\n"; ????cout << "Third min = " << thirdmin << "\n"; } // Driver code int main() { ????int array[] = {4, 9, 1, 32, 12}; ????int n = sizeof(array) / sizeof(array[0]); ????Print3Smallest(array, n); ????return 0; } ``` ## Java ```java // Java program to find the first, second // and third minimum element in an array import java.util.*; public class GFG { ????static void Print3Smallest(int array[], int n) ????{ ????????????int firstmin = Integer.MAX_VALUE; ????????????int secmin = Integer.MAX_VALUE;? ????????????int thirdmin = Integer.MAX_VALUE; ????????????for (int i = 0; i < n; i++) ????????????{ ????????????????/* Check if current element is less than ????????????????firstmin, then update first, second and ????????????????third */ ????????????????if (array[i] < firstmin) ????????????????{ ????????????????????thirdmin = secmin; ????????????????????secmin = firstmin; ????????????????????firstmin = array[i]; ????????????????} ????????????????/* Check if current element is less than ????????????????secmin then update second and third */ ????????????????else if (array[i] < secmin) ????????????????{ ????????????????????thirdmin = secmin; ????????????????????secmin = array[i]; ????????????????} ????????????????/* Check if current element is less than ????????????????then update third */ ????????????????else if (array[i] < thirdmin) ????????????????????thirdmin = array[i]; ????????????} ????????????System.out.println("First min = " + firstmin ); ????????????System.out.println("Second min = " + secmin ); ????????????System.out.println("Third min = " + thirdmin ); ????} ????// Driver code ????public static void main(String[] args) ????{ ????????????int array[] = {4, 9, 1, 32, 12}; ????????????int n = array.length; ????????????Print3Smallest(array, n); ????} } // This code is contributed by? // Sam007 ``` ## Python3 ```py # A Python program to find the first, # second and third minimum element? # in an array MAX = 100000 def Print3Smallest(arr, n): ????firstmin = MAX ????secmin = MAX ????thirdmin = MAX ????for i in range(0, n): ????????# Check if current element ????????# is less than firstmin,? ????????# then update first,second ????????# and third ????????if arr[i] < firstmin: ????????????thirdmin = secmin ????????????secmin = firstmin ????????????firstmin = arr[i] ????????# Check if current element is ????????# less than secmin then update ????????# second and third ????????elif arr[i] < secmin: ????????????thirdmin = secmin ????????????secmin = arr[i] ????????# Check if current element is ????????# less than,then upadte third ????????elif arr[i] < thirdmin: ????????????thirdmin = arr[i] ????print("First min = ", firstmin) ????print("Second min = ", secmin) ????print("Third min = ", thirdmin) # driver program arr = [4, 9, 1, 32, 12] n = len(arr) Print3Smallest(arr, n) # This code is contributed by Shrikant13\. ``` ## C# ```cs // C# program to find the first, second // and third minimum element in an array using System; class GFG { static void Print3Smallest(int []array, int n) ????{ ????????????int firstmin = int.MaxValue; ????????????int secmin = int.MaxValue;? ????????????int thirdmin = int.MaxValue; ????????????for (int i = 0; i < n; i++) ????????????{ ????????????????/* Check if current element is less than ????????????????firstmin, then update first, second and ????????????????third */ ????????????????if (array[i] < firstmin) ????????????????{ ????????????????????thirdmin = secmin; ????????????????????secmin = firstmin; ????????????????????firstmin = array[i]; ????????????????} ????????????????/* Check if current element is less than ????????????????secmin then update second and third */ ????????????????else if (array[i] < secmin) ????????????????{ ????????????????????thirdmin = secmin; ????????????????????secmin = array[i]; ????????????????} ????????????????/* Check if current element is less than ????????????????then update third */ ????????????????else if (array[i] < thirdmin) ????????????????????thirdmin = array[i]; ????????????} ????????????Console.WriteLine("First min = " + firstmin ); ????????????Console.WriteLine("Second min = " + secmin ); ????????????Console.WriteLine("Third min = " + thirdmin ); ????} ????// Driver code ????static void Main() ????{ ????int []array = new int[]{4, 9, 1, 32, 12}; ????int n = array.Length; ????Print3Smallest(array, n); ????} } // This code is contributed by Sam007 ``` ## PHP ```php <?php // php program to find the first, second // and third minimum element in an array function Print3Smallest($array, $n) { ????$MAX = 100000; ????$firstmin = $MAX; ????$secmin = $MAX; ????$thirdmin = $MAX; ????for ($i = 0; $i < $n; $i++) ????{ ????????/* Check if current element is less than ????????firstmin, then update first, second and ????????third */ ????????if ($array[$i] < $firstmin) ????????{ ????????????$thirdmin = $secmin; ????????????$secmin = $firstmin; ????????????$firstmin = $array[$i]; ????????} ????????/* Check if current element is less than ????????secmin then update second and third */ ????????else if ($array[$i] < $secmin) ????????{ ????????????$thirdmin = $secmin; ????????????$secmin = $array[$i]; ????????} ????????/* Check if current element is less than ????????then update third */ ????????else if ($array[$i] < $thirdmin) ????????????$thirdmin = $array[$i]; ????} ????echo "First min = ".$firstmin."\n"; ????echo "Second min = ".$secmin."\n"; ????echo "Third min = ".$thirdmin."\n"; } // Driver code ????$array= array(4, 9, 1, 32, 12); ????$n = sizeof($array) / sizeof($array[0]); ????Print3Smallest($array, $n); // This code is contributed by mits ?> ``` Output: ``` First min = 1 Second min = 4 Third min = 9 ``` * * * * * *