给定一个不同整数的数组，打印数组中存在的数字的正负值的所有对。 注： 成对的顺序无关紧要。 例如：
null
Input: arr[] = { 1, -3, 2, 3, 6, -1 }Output: -1 1 -3 3Input: arr[] = { 4, 8, 9, -4, 1, -1, -8, -9 }Output: -1 1 -4 4 -8 8 -9 9
A. 幼稚的方法 是运行两个循环，即使用外环考虑数组中的每个元素，并使用内循环搜索数组中相应的正/负值。同样，找到所有的配对。这种方法的时间复杂度为O（n 2. ). A. 更好的方法 就是使用 分类 i、 e.首先对数组进行排序，然后对每个负元素进行二进制搜索，以找到对应的（+ve编号）。如果找到了，打印那一对。如果当前元素为正数，则中断该循环，因为之后将出现所有正数。
C++
// CPP program to find pairs of positive // and negative values present in an array. #include <bits/stdc++.h> using namespace std; void printPairs( int arr[], int n) { bool pair_exists = false ; // Sort the array sort(arr, arr + n); // Traverse the array for ( int i = 0; i < n; i++) { // For every arr[i] < 0 element, // do a binary search for arr[i] > 0. if (arr[i] < 0) { // If found, print the pair. if (binary_search(arr, arr + n, -arr[i])) { cout << arr[i] << ", " << -arr[i] << endl; pair_exists = true ; } } else break ; } if (pair_exists == false ) cout << "No such pair exists" ; } // Driver code int main() { int arr[] = { 4, 8, 9, -4, 1, -1, -8, -9 }; int n = sizeof (arr) / sizeof (arr[0]); printPairs(arr, n); return 0; } |
JAVA
// Java program to find pairs // of positive and negative // values present in an array. import java.util.*; class GFG { static void printPairs( int arr[], int n) { boolean pair_exists = false ; // Sort the array Arrays.sort(arr); // Traverse the array for ( int i = 0 ; i < n; i++) { // For every arr[i] < 0 element, // do a binary search for arr[i] > 0. if (arr[i] < 0 ) { // If found, print the pair. if (java.util.Arrays.binarySearch(arr, -arr[i])!=- 1 ) { System.out.println(arr[i] + ", " + -arr[i] ); pair_exists = true ; } } else break ; } if (pair_exists == false ) System.out.println( "No such pair exists" ); } // Driver code public static void main(String args[]) { int arr[] = { 4 , 8 , 9 , - 4 , 1 , - 1 , - 8 , - 9 }; int n =arr.length; printPairs(arr, n); } } // This code is contributed // by Arnab Kundu |
Python 3
# Python3 program to find pairs of positive # and negative values present in an array. # function for binary search def binary_search(a, x, lo = 0 , hi = None ): if hi is None : hi = len (a) while lo < hi: mid = (lo + hi) / / 2 midval = a[mid] if midval < x: lo = mid + 1 elif midval > x: hi = mid else : return mid return - 1 def printPairs(arr, n): pair_exists = False # Sort the array arr.sort() # Traverse the array for i in range (n): # For every arr[i] < 0 element, # do a binary search for arr[i] > 0. if (arr[i] < 0 ): # If found, print the pair. if (binary_search(arr, - arr[i])): print (arr[i] , ", " , - arr[i]) pair_exists = True else : break if (pair_exists = = False ): print ( "No such pair exists" ) # Driver code if __name__ = = '__main__' : arr = [ 4 , 8 , 9 , - 4 , 1 , - 1 , - 8 , - 9 ] n = len (arr) printPairs(arr, n) # this code is contributed by ash264 |
C#
// C# program to find pairs // of positive and negative // values present in an array. using System; public class GFG{ static void printPairs( int []arr, int n) { bool pair_exists = false ; // Sort the array Array.Sort(arr); // Traverse the array for ( int i = 0; i < n; i++) { // For every arr[i] < 0 element, // do a binary search for arr[i] > 0. if (arr[i] < 0) { // If found, print the pair. if (Array.BinarySearch(arr, -arr[i])!=-1) { Console.WriteLine(arr[i] + ", " + -arr[i] ); pair_exists = true ; } } else break ; } if (pair_exists == false ) Console.WriteLine( "No such pair exists" ); } // Driver code public static void Main() { int []arr = { 4, 8, 9, -4, 1, -1, -8, -9 }; int n =arr.Length; printPairs(arr, n); } } // This code is contributed by 29AjayKumar |
Javascript
<script> // JavaScript program to find pairs of positive // and negative values present in an array. function printPairs(arr, n) { let pair_exists = false ; // Sort the array arr.sort((a, b) => a - b); // Traverse the array for (let i = 0; i < n; i++) { // For every arr[i] < 0 element, // do a binary search for arr[i] > 0. if (arr[i] < 0) { // If found, print the pair. if (arr.includes(-arr[i])) { document.write(arr[i] + ", " + -arr[i] + "<br>" ); pair_exists = true ; } } else break ; } if (pair_exists == false ) document.write( "No such pair exists" ); } // Driver code let arr = [4, 8, 9, -4, 1, -1, -8, -9]; let n = arr.length; printPairs(arr, n); </script> |
输出：
-9, 9-8, 8-4, 4-1, 1
时间复杂性： O（nlogn） 一 有效的方法 就是使用 散列 .以下是所需的步骤：
- 开始遍历数组。
- 将所有psoitve值存储在无序的_集中。
- 检查每个负元素，是否在集合中存在对应的正元素。
- 如果是，请打印一对
- 此外，维护一个标志以检查是否不存在这样的对。
C++
// CPP program to find pairs of positive // and negative values present in an array #include <bits/stdc++.h> using namespace std; // Function to print pairs of positive // and negative values present in the array void printPairs( int arr[], int n) { unordered_set< int > pairs; bool pair_exists = false ; // Store all the positive elements // in the unordered_set for ( int i = 0; i < n; i++) if (arr[i] > 0) pairs.insert(arr[i]); // Start traversing the array for ( int i = 0; i < n; i++) { // Check if the positive value of current // element exists in the set or not if (arr[i] < 0) if (pairs.find(-arr[i]) != pairs.end()) { // Print that pair cout << arr[i] << ", " << -arr[i] << endl; pair_exists = true ; } } if (pair_exists == false ) cout << "No such pair exists" ; } // Driver code int main() { int arr[] = { 4, 8, 9, -4, 1, -1, -8, -9 }; int n = sizeof (arr) / sizeof (arr[0]); printPairs(arr, n); return 0; } |
JAVA
// Java program to find pairs of positive // and negative values present in an array import java.util.*; class GFG { // Function to print pairs of positive // and negative values present in the array static void printPairs( int arr[], int n) { Set<Integer> pairs = new HashSet<Integer>(); boolean pair_exists = false ; // Store all the positive elements // in the unordered_set for ( int i = 0 ; i < n; i++) if (arr[i] > 0 ) pairs.add(arr[i]); // Start traversing the array for ( int i = 0 ; i < n; i++) { // Check if the positive value of current // element exists in the set or not if (arr[i] < 0 ) if (pairs.contains(-arr[i])) { // Print that pair System.out.println(arr[i] + ", " + -arr[i]); pair_exists = true ; } } if (pair_exists == false ) System.out.println( "No such pair exists" ); } // Driver code public static void main(String args[]) { int arr[] = { 4 , 8 , 9 , - 4 , 1 , - 1 , - 8 , - 9 }; int n = arr.length; printPairs(arr, n); } } // This code is contributed by Arnab Kundu |
Python3
# Python3 program to find pairs of positive # and negative values present in an array # Function to print pairs of positive # and negative values present in the array def printPairs(arr, n): pairs = set () pair_exists = False # Store all the positive elements # in the unordered_set for i in range ( 0 , n): if arr[i] > 0 : pairs.add(arr[i]) # Start traversing the array for i in range ( 0 , n): # Check if the positive value of current # element exists in the set or not if arr[i] < 0 : if ( - arr[i]) in pairs: # Print that pair print ( "{}, {}" . format (arr[i], - arr[i])) pair_exists = True if pair_exists = = False : print ( "No such pair exists" ) # Driver code if __name__ = = "__main__" : arr = [ 4 , 8 , 9 , - 4 , 1 , - 1 , - 8 , - 9 ] n = len (arr) printPairs(arr, n) # This code is contributed by Rituraj Jain |
C#
// C# program to find pairs of positive // and negative values present in an array using System; using System.Collections.Generic; class GFG { // Function to print pairs of positive // and negative values present in the array static void printPairs( int []arr, int n) { HashSet< int > pairs = new HashSet< int >(); bool pair_exists = false ; // Store all the positive elements // in the unordered_set for ( int i = 0; i < n; i++) if (arr[i] > 0) pairs.Add(arr[i]); // Start traversing the array for ( int i = 0; i < n; i++) { // Check if the positive value of current // element exists in the set or not if (arr[i] < 0) if (pairs.Contains(-arr[i])) { // Print that pair Console.WriteLine(arr[i] + ", " + -arr[i]); pair_exists = true ; } } if (pair_exists == false ) Console.WriteLine( "No such pair exists" ); } // Driver code public static void Main(String []args) { int []arr = { 4, 8, 9, -4, 1, -1, -8, -9 }; int n = arr.Length; printPairs(arr, n); } } // This code is contributed by PrinciRaj1992 |
Javascript
<script> // JavaScript program to find pairs of positive // and negative values present in an array // Function to print pairs of positive // and negative values present in the array function printPairs(arr,n) { let pairs = new Set(); let pair_exists = false ; // Store all the positive elements // in the unordered_set for (let i = 0; i < n; i++) if (arr[i] > 0) pairs.add(arr[i]); // Start traversing the array for (let i = 0; i < n; i++) { // Check if the positive value of current // element exists in the set or not if (arr[i] < 0) if (pairs.has(-arr[i])) { // Print that pair document.write(arr[i] + ", " + -arr[i]+ "<br>" ); pair_exists = true ; } } if (pair_exists == false ) document.write( "No such pair exists" ); } // Driver code let arr=[4, 8, 9, -4, 1, -1, -8, -9]; let n = arr.length; printPairs(arr, n); // This code is contributed by avanitrachhadiya2155 </script> |
输出：
-4, 4-1, 1-8, 8-9, 9
时间复杂性： O（n）
© 版权声明
文章版权归作者所有，未经允许请勿转载。
THE END
![关于”PostgreSQL错误：关系[表]不存在“问题的原因和解决方案-yiteyi-C++库](https://www.yiteyi.com/wp-content/themes/zibll/img/thumbnail.svg)
