交替的低位上弦排序

给定一个包含小写和大写字母的字符串。以这样一种方式对它进行排序，以使大写字母和小写字母以交替的方式出现，但以一种排序的方式出现。
例子：

Input : bAwutndekWEdkd
Output :AbEdWddekkntuw
Explanation:
Here we can see that letter ‘A’, ’E’, ’W’ are sorted 
as well as letters “b, d, d, d, e, k, k, n, t, u, w” are sorted 
but both appears alternately in the string as far as possible.

Input :abbfDDhGFBvdFDGBNDasZVDFjkb
Output :BaBaDbDbDbDdDfFhFjFkGsGvNVZ

1)在数组lCount []中计算小写字符
2)在另一个数组uCount []中计算大写字符
3)使用lCount []和uCount []修改字符串

C++

// C++ program for unusul string sorting
#include 
using namespace std;
#define MAX 26
 
// Function for alternate sorting of string
void alternateSort(string& s)
{
    int n = s.length();
 
    // Count occurrences of individual lower case and
    // upper case characters
    int lCount[MAX] = { 0 }, uCount[MAX] = { 0 };
    for (int i = 0; i < n; i++) {
        if (isupper(s[i]))
            uCount[s[i] - 'A']++;
        else
            lCount[s[i] - 'a']++;
    }
 
    // Traverse through count arrays and one by one
    // pick characters.  Below loop takes O(n) time
    // considering the MAX is constant.
    int i = 0, j = 0, k = 0;
    while (k < n) {
        while (i < MAX && uCount[i] == 0)
            i++;
        if (i < MAX) {
            s[k++] = 'A' + i;
            uCount[i]--;
        }
 
        while (j < MAX && lCount[j] == 0)
            j++;
        if (j < MAX) {
            s[k++] = 'a' + j;
            lCount[j]--;
        }
    }
}
 
// Driver code
int main()
{
    string str = "bAwutndekWEdkd";
    alternateSort(str);
    cout << str << "\n";
}

Java

// Java program for
// unusual string sorting
import java.util.*;
import java.lang.*;
 
public class GfG{
 
private final static int MAX = 100;
 
// Function for alternate
// sorting of string
public static String alternateSort(String s1)
{
    int n = s1.length();
 
    char[] s = s1.toCharArray();
 
    // Count occurrences of
    // individual lower case and
    // upper case characters
    int[] lCount = new int[MAX];
    int[] uCount = new int[MAX];
 
    for (int i = 0; i < n; i++) {
 
        if (Character.isUpperCase(s[i]))
            uCount[s[i] - 'A']++;
        else
            lCount[s[i] - 'a']++;
    }
 
    // Traverse through count
    // arrays and one by one
    // pick characters.
    // Below loop takes O(n) time
    // considering the MAX is constant.
    int i = 0, j = 0, k = 0;
    while (k < n)
    {
 
        while (i < MAX && uCount[i] == 0)
                i++;
 
        if (i < MAX) {
                s[k++] = (char)('A' + i);
                uCount[i]--;
            }
 
        while (j < MAX && lCount[j] == 0)
                j++;
 
        if (j < MAX) {
                s[k++] = (char)('a' + j);
                lCount[j]--;
            }
        }
         
        return (new String(s));
    }
     
// Driver function
public static void main(String argc[]){
 
    String str = "bAwutndekWEdkd";
    System.out.println(alternateSort(str));
}
     
}
 
 
// This code is contributed by Sagar Shukla

C#

// C# program for unusual string sorting
using System;
 
public class GFG {
 
    private static int MAX = 100;
     
    // Function for alternate
    // sorting of string
    static String alternateSort(String s1)
    {
        int n = s1.Length;
        int l = 0, j = 0, k = 0;
     
        char[] s = s1.ToCharArray();
     
        // Count occurrences of
        // individual lower case and
        // upper case characters
        int[] lCount = new int[MAX];
        int[] uCount = new int[MAX];
     
        for (int i = 0; i < n; i++) {
     
            if (char.IsUpper(s[i]))
                uCount[s[i] - 'A']++;
            else
                lCount[s[i] - 'a']++;
        }
     
        // Traverse through count
        // arrays and one by one
        // pick characters.
        // Below loop takes O(n) time
        // considering the MAX is constant.
         
        while (k < n)
        {
     
            while (l < MAX && uCount[l] == 0)
                l++;
     
            if (l < MAX) {
                s[k++] = (char)('A' + l);
                uCount[l]--;
            }
     
            while (j < MAX && lCount[j] == 0)
                j++;
     
            if (j < MAX) {
                s[k++] = (char)('a' + j);
                lCount[j]--;
            }
        }
             
        return (new String(s));
    }
         
    // Driver function
    public static void Main()
    {
        String str = "bAwutndekWEdkd";
         
        Console.Write(alternateSort(str));
    }
}
 
// This code is contributed by parashar.

Python3

# Python3 program for
# unusul string sorting
MAX = 26
 
# Function for alternate
# sorting of string
def alternateSort(s):
   
    n = len(s)
 
    # Count occurrences of
    # individual lower case and
       # upper case characters
    lCount = [0 for i in range(MAX)]
    uCount = [0 for i in range(MAX)]
    s = list(s)
     
    for i in range(n):
        if(s[i].isupper()):
            uCount[ord(s[i]) -
                   ord('A')] += 1
        else:
            lCount[ord(s[i]) -
                   ord('a')] += 1
 
    # Traverse through count
    # arrays and one by one
    # pick characters. Below
    # loop takes O(n) time
    # considering the MAX
    # is constant.
    i = 0
    j = 0
    k = 0
 
    while(k < n):
        while(i < MAX and
              uCount[i] == 0):
            i += 1
        if(i < MAX):
            s[k] = chr(ord('A') + i)
            k += 1
            uCount[i] -= 1
        while(j < MAX and
              lCount[j] == 0):
            j += 1
        if(j < MAX):
            s[k] = chr(ord('a') + j)
            k += 1
            lCount[j] -= 1
 
    print("".join(s))
 
# Driver code
str = "bAwutndekWEdkd"
alternateSort(str)
 
# This code is contributed by avanitrachhadiya2155

输出：

AbEdWddekkntuw

时间复杂度： O(n)