生成一个由满足给定条件的字符“a”和“b”组成的字符串

给定两个整数A和B ，任务是生成并打印一个字符串str ，使得：

str只能包含字符'a'和'b' 。
str的长度为A + B ，字符“a”的出现等于A ，字符“b”的出现等于B
子字符串“aaa”或“bbb”不得出现在str中。

请注意，对于A和B的给定值，始终可以生成有效的字符串。
例子：

Input: A = 1, B = 2
Output: abb
“abb”, “bab” and “bba” are all valid strings.
Input: A = 4, B = 1
Output: aabaa

编程需要懂一点英语

方法：

如果发生（a）>发生（b）然后附加“aab”
如果发生（b）>发生（a）然后附加“bba”
如果发生（a）=发生（b）然后附加“ab”

由于我们在每次迭代中将'a'和'b'的出现次数之间的差异最多减少 1 次，因此保证“bba”和“aab”之后不会分别跟随“aab”和“bba” 。
下面是上述方法的实现：

C++

// C++ implementation of the approach
#include 
using namespace std;
 
// Function to generate and print the required string
void generateString(int A, int B)
{
    string rt;
    while (0 < A || 0 < B) {
 
        // More 'b', append "bba"
        if (A < B) {
            if (0 < B--)
                rt.push_back('b');
            if (0 < B--)
                rt.push_back('b');
            if (0 < A--)
                rt.push_back('a');
        }
 
        // More 'a', append "aab"
        else if (B < A) {
            if (0 < A--)
                rt.push_back('a');
            if (0 < A--)
                rt.push_back('a');
            if (0 < B--)
                rt.push_back('b');
        }
 
        // Equal number of 'a' and 'b'
        // append "ab"
        else {
            if (0 < A--)
                rt.push_back('a');
            if (0 < B--)
                rt.push_back('b');
        }
    }
    cout << rt;
}
 
// Driver code
int main()
{
    int A = 2, B = 6;
    generateString(A, B);
 
    return 0;
}

Java

// Java implementation of the approach
class GFG
{
 
    // Function to generate and
    // print the required string
    static void generateString(int A, int B)
    {
        String rt = "";
        while (0 < A || 0 < B)
        {
 
            // More 'b', append "bba"
            if (A < B)
            {
                if (0 < B--)
                {
                    rt += ('b');
                }
                if (0 < B--)
                {
                    rt += ('b');
                }
                if (0 < A--)
                {
                    rt += ('a');
                }
            }
             
            // More 'a', append "aab"
            else if (B < A)
            {
                if (0 < A--)
                {
                    rt += ('a');
                }
                if (0 < A--)
                {
                    rt += ('a');
                }
                if (0 < B--)
                {
                    rt += ('b');
                }
            }
             
            // Equal number of 'a' and 'b'
            // append "ab"
            else
            {
                if (0 < A--)
                {
                    rt += ('a');
                }
                if (0 < B--)
                {
                    rt += ('b');
                }
            }
        }
        System.out.println(rt);
    }
 
    // Driver code
    public static void main(String[] args)
    {
        int A = 2, B = 6;
        generateString(A, B);
    }
}
 
// This code is contributed
// by PrinciRaj1992

Python 3

# Python 3 implementation of the approach
 
# Function to generate and print
# the required string
def generateString(A, B):
 
    rt = ""
    while (0 < A or 0 < B) :
 
        # More 'b', append "bba"
        if (A < B) :
            if (0 < B):
                rt = rt +'b'
                B -= 1
            if (0 < B):
                rt += 'b'
                B -= 1
            if (0 < A):
                rt += 'a'
                A -= 1
 
        # More 'a', append "aab"
        elif (B < A):
            if (0 < A):
                rt += 'a'
                A -= 1
            if (0 < A):
                rt += 'a'
                A -= 1
            if (0 < B):
                rt += 'b'
                B -= 1
 
        # Equal number of 'a' and 'b'
        # append "ab"
        else :
            if (0 < A):
                rt += 'a'
                A -= 1
            if (0 < B):
                rt += 'b'
                B -= 1
    print(rt)
 
# Driver code
if __name__ == "__main__":
     
    A = 2
    B = 6
    generateString(A, B)
 
# This code is contributed by ita_c

C#

// C# implementation of the approach
using System;
 
class GFG
{
 
    // Function to generate and
    // print the required string
    static void generateString(int A, int B)
    {
        string rt = "";
        while (0 < A || 0 < B)
        {
 
            // More 'b', append "bba"
            if (A < B)
            {
                if (0 < B--)
                {
                    rt += ('b');
                }
                if (0 < B--)
                {
                    rt += ('b');
                }
                if (0 < A--)
                {
                    rt += ('a');
                }
            }
             
            // More 'a', append "aab"
            else if (B < A)
            {
                if (0 < A--)
                {
                    rt += ('a');
                }
                if (0 < A--)
                {
                    rt += ('a');
                }
                if (0 < B--)
                {
                    rt += ('b');
                }
            }
             
            // Equal number of 'a' and 'b'
            // append "ab"
            else
            {
                if (0 < A--)
                {
                    rt += ('a');
                }
                if (0 < B--)
                {
                    rt += ('b');
                }
            }
        }
        Console.WriteLine(rt);
    }
 
    // Driver code
    public static void Main()
    {
        int A = 2, B = 6;
        generateString(A, B);
    }
}
 
// This code is contributed by Ryuga

PHP

Javascript

输出：

bbabbabb