给定一个由N 个不同整数组成的数组arr[] ,任务是将给定的数组转换为前 N 个非负整数的序列,即[0, N – 1]使得元素的顺序相同,即0放置在最小数组元素的索引处, 1放置在第二个最小元素的索引处,依此类推。
例子:
Input: arr[] = {10, 40, 20}
Output: 0 2 1
Input: arr[] = {5, 10, 40, 30, 20}
Output: 0 1 4 3 2
基于散列的方法:有关基于散列的方法,请参阅本文的 Set 1 帖子。
时间复杂度: O(N* log N)
辅助空间: O(N)
Vector Of Pairs Based Approach:有关使用对向量的方法,请参阅本文的 Set 2 帖子。
时间复杂度: O(N* log N)
辅助空间: O(N)
基于二分搜索的方法:按照以下步骤解决问题:
- 初始化一个数组,比如brr[]并将数组arr[] 的所有元素存储到brr[] 中。
- 按升序对数组brr[]进行排序。
- 遍历给定阵列ARR []以及对于每个元素,即,编曲[I]找到ARR [I]中的阵列的BRR LOWER_BOUND []和打印的是作为结果为当前元素的索引。
下面是上述方法的实现:
C++
// C++ program for the above approach
#include
using namespace std;
// Function to find the reduced form
// of the given array arr[]
void convert(int arr[], int n)
{
// Stores the sorted form of the
// the given array arr[]
int brr[n];
for (int i = 0; i < n; i++)
brr[i] = arr[i];
// Sort the array brr[]
sort(brr, brr + n);
// Traverse the given array arr[]
for (int i = 0; i < n; i++) {
int l = 0, r = n - 1, mid;
// Perform the Binary Search
while (l <= r) {
// Calculate the value of
// mid
mid = (l + r) / 2;
if (brr[mid] == arr[i]) {
// Print the current
// index and break
cout << mid << ' ';
break;
}
// Update the value of l
else if (brr[mid] < arr[i]) {
l = mid + 1;
}
// Update the value of r
else {
r = mid - 1;
}
}
}
}
// Driver Code
int main()
{
int arr[] = { 10, 20, 15, 12, 11, 50 };
int N = sizeof(arr) / sizeof(arr[0]);
convert(arr, N);
return 0;
}
Java
// Java program for the above approach
import java.io.*;
import java.lang.*;
import java.util.*;
public class GFG
{
// Function to find the reduced form
// of the given array arr[]
static void convert(int arr[], int n)
{
// Stores the sorted form of the
// the given array arr[]
int brr[] = new int[n];
for (int i = 0; i < n; i++)
brr[i] = arr[i];
// Sort the array brr[]
Arrays.sort(brr);
// Traverse the given array arr[]
for (int i = 0; i < n; i++) {
int l = 0, r = n - 1, mid;
// Perform the Binary Search
while (l <= r) {
// Calculate the value of
// mid
mid = (l + r) / 2;
if (brr[mid] == arr[i]) {
// Print the current
// index and break
System.out.print(mid + " ");
break;
}
// Update the value of l
else if (brr[mid] < arr[i]) {
l = mid + 1;
}
// Update the value of r
else {
r = mid - 1;
}
}
}
}
// Driver Code
public static void main(String[] args)
{
int arr[] = { 10, 20, 15, 12, 11, 50 };
int N = arr.length;
convert(arr, N);
}
}
// This code is contributed by Kingash.
Python3
# Python3 program for the above approach
# Function to find the reduced form
# of the given array arr[]
def convert(arr, n):
# Stores the sorted form of the
# the given array arr[]
brr = [i for i in arr]
# Sort the array brr[]
brr = sorted(brr)
# Traverse the given array arr[]
for i in range(n):
l, r, mid = 0, n - 1, 0
# Perform the Binary Search
while (l <= r):
# Calculate the value of
# mid
mid = (l + r) // 2
if (brr[mid] == arr[i]):
# Prthe current
# index and break
print(mid,end=" ")
break
# Update the value of l
elif (brr[mid] < arr[i]):
l = mid + 1
# Update the value of r
else:
r = mid - 1
# Driver Code
if __name__ == '__main__':
arr=[10, 20, 15, 12, 11, 50]
N = len(arr)
convert(arr, N)
# This code is contributed by mohit kumar 29.
C#
// C# program for the above approach
using System;
class GFG{
// Function to find the reduced form
// of the given array arr[]
static void convert(int[] arr, int n)
{
// Stores the sorted form of the
// the given array arr[]
int[] brr = new int[n];
for(int i = 0; i < n; i++)
brr[i] = arr[i];
// Sort the array brr[]
Array.Sort(brr);
// Traverse the given array arr[]
for(int i = 0; i < n; i++)
{
int l = 0, r = n - 1, mid;
// Perform the Binary Search
while (l <= r)
{
// Calculate the value of
// mid
mid = (l + r) / 2;
if (brr[mid] == arr[i])
{
// Print the current
// index and break
Console.Write(mid + " ");
break;
}
// Update the value of l
else if (brr[mid] < arr[i])
{
l = mid + 1;
}
// Update the value of r
else
{
r = mid - 1;
}
}
}
}
// Driver Code
public static void Main(string[] args)
{
int[] arr = { 10, 20, 15, 12, 11, 50 };
int N = arr.Length;
convert(arr, N);
}
}
// This code is contributed by ukasp
Javascript
输出:
0 4 3 2 1 5
时间复杂度: O(N * log N)
辅助空间: O(N)
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