# 用数组的总大小和该元素的频率之差替换每个元素

2021年4月29日18:10:04 发表评论 490 次浏览

## 本文概述

``````Input: arr[] = { 1, 2, 5, 2, 2, 5, 4 }
Output: 6 4 5 4 4 5 6
Size of the array is 7.
The frequency of 1 is 1. So replace it by 7-1 = 6
The frequency of 2 is 3. So replace it by 7-3 = 4

Input: arr[] = { 4, 5, 4, 5, 6, 6, 6 }
Output: 5 5 5 5 4 4 4``````

1. 拿一个哈希图, 它将存储数组中所有元素的频率。
2. 现在, 再次遍历。
3. 现在, 用数组总大小及其频率之差替换所有元素。
4. 打印修改后的数组。

## C ++

``````//C++ program to Replace each element
//by the difference of the total size
//of the array and its frequency
#include <bits/stdc++.h>
using namespace std;

//Function to replace the elements
void ReplaceElements( int arr[], int n)
{
//Hash map which will store the
//frequency of the elements of the array.
unordered_map<int , int> mp;

for ( int i = 0; i <n; ++i)

//Increment the frequency
//of the element by 1.
mp[arr[i]]++;

//Replace every element by its frequency
for ( int i = 0; i <n; ++i)
arr[i] = n - mp[arr[i]];

}

//Driver code
int main()
{
int arr[] = { 1, 2, 5, 2, 2, 5, 4 };
int n = sizeof (arr) /sizeof (arr);

ReplaceElements(arr, n);

//Print the modified array.
for ( int i = 0; i <n; ++i)
cout <<arr[i] <<" " ;

return 0;
}``````

## Java

``````//Java program to Replace each element
//by the difference of the total size
//of the array and its frequency
import java.util.*;

class GFG
{

//Function to replace the elements
static void ReplaceElements( int arr[], int n)
{
//Hash map which will store the
//frequency of the elements of the array.
HashMap<Integer, Integer> mp = new HashMap<>();

for ( int i = 0 ; i <n; i++)
{

//Increment the frequency
//of the element by 1.
if (!mp.containsKey(arr[i]))
{
mp.put(arr[i], 1 );
}
else
{
mp.put(arr[i], mp.get(arr[i]) + 1 );
}
}

//Replace every element by its frequency
for ( int i = 0 ; i <n; ++i)
{
arr[i] = n - mp.get(arr[i]);
}

}

//Driver code
public static void main(String[] args)
{
int arr[] = { 1 , 2 , 5 , 2 , 2 , 5 , 4 };
int n = arr.length;

ReplaceElements(arr, n);

//Print the modified array.
for ( int i = 0 ; i <n; ++i)
{
System.out.print(arr[i] + " " );
}
}
}

//This code contributed by Rajput-Ji``````

## Python3

``````# Python3 program to Replace each element
# by the difference of the total size
# of the array and its frequency

# Function to replace the elements
def ReplaceElements(arr, n):

# Hash map which will store the
# frequency of the elements of the array.
mp = dict ()

for i in range (n):

# Increment the frequency
# of the element by 1.
mp[arr[i]] = mp.get(arr[i], 0 ) + 1

# Replace every element by its frequency
for i in range (n):
arr[i] = n - mp[arr[i]]

# Driver code
arr = [ 1 , 2 , 5 , 2 , 2 , 5 , 4 ]
n = len (arr)

ReplaceElements(arr, n)

# Print the modified array.
for i in range (n):
print (arr[i], end = " " )

# This code is contributed by mohit kumar``````

## C#

``````//C# program to Replace each element
//by the difference of the total size
//of the array and its frequency
using System;
using System.Collections.Generic;

class GFG
{

//Function to replace the elements
static void ReplaceElements( int []arr, int n)
{
//Hash map which will store the
//frequency of the elements of the array.
Dictionary<int , int> mp = new Dictionary<int , int>();

for ( int i = 0; i <n; i++)
{

//Increment the frequency
//of the element by 1.
if (!mp.ContainsKey(arr[i]))
{
}
else
{
var a = mp[arr[i]] + 1;
mp.Remove(arr[i]);
}
}

//Replace every element by its frequency
for ( int i = 0; i <n; ++i)
{
arr[i] = n - mp[arr[i]];
}

}

//Driver code
public static void Main()
{
int []arr = {1, 2, 5, 2, 2, 5, 4};
int n = arr.Length;

ReplaceElements(arr, n);

//Print the modified array.
for ( int i = 0; i <n; ++i)
{
Console.Write(arr[i] + " " );
}
}
}

/* This code contributed by PrinciRaj1992 */``````

``6 4 5 4 4 5 6`` 