将给定整数转换为数字总和为偶数的奇数的最小删除| 2套

给定一个正整数N ，任务是找到将N转换为数字总和为偶数的奇数所需去除的最小位数。如果不可能，则打印“不可能”。

例子：

Input: N = 12345
Output: 1
Explanation:
Removing the digit 3 modifies N to 1245. 
Since the sum of digits of N is 14 and N is odd, the required output is 1.

Input: N = 222
Output: Not Possible

方法：这个想法是利用奇数的偶数相加得到偶数这一事实。请按照以下步骤解决问题：

• 计算整数N 中存在的总奇数和偶数位数 并将它们存储在变量中，比如奇数和偶数。
• 如果Odd = 0 ，则不能通过删除任意数量的数字将整数转换为奇数。因此，打印“不可能” 。
• 否则，如果Odd = 1 ，则要使数字之和为偶数，则必须删除该奇数，从而产生偶数。因此，打印“不可能”。
• 现在，计算最后一次出现奇数后要删除的位数，并将其存储在变量中，例如ans 。
• 如果Odd是奇数，则将ans的计数加一，因为必须删除一个奇数才能使和为偶数。
• 最后，如果以上情况都不满足，则打印ans 。

下面是上述方法的实现：

C++

// C++ implementation of the above approach
#include 
using namespace std;
 
// Function to find minimum count of digits
// required to be remove to make N odd and
// the sum of digits of N even
void minOperations(string& N)
{
 
    // Stores count of even digits
    int even = 0;
 
    // Stores count of odd digits
    int odd = 0;
 
    // Iterate over the digits of N
    for (auto it : N) {
 
        // If current digit is even
        if ((it - '0') % 2 == 0) {
 
            // Update even
            even++;
        }
 
        // Otherwise
        else {
 
            // Update odd
            odd++;
        }
    }
 
    // Base conditions
    if (odd == 0 || odd == 1) {
        cout << "Not Possible"
             << "\n";
    }
 
    else {
 
        // Stores count of digits required to be
        // removed to make N odd and the sum of
        // digits of N even
        int ans = 0;
 
        // Iterate over the digits of N
        for (auto it : N) {
 
            // If current digit is even
            if ((it - '0') % 2 == 0) {
 
                // Update ans
                ans++;
            }
 
            // Otherwise,
            else {
 
                // Update ans
                ans = 0;
            }
        }
 
        // If count of odd digits is odd
        if (odd % 2) {
 
            // Update ans
            ans++;
        }
 
        // Finally print the ans
        cout << ans << endl;
    }
}
 
// Driver code
int main()
{
 
    // Input string
    string N = "12345";
 
    // Function call
    minOperations(N);
}

Java

// Java implementation of the above approach
import java.util.*;
class GFG
{
 
// Function to find minimum count of digits
// required to be remove to make N odd and
// the sum of digits of N even
static void minOperations(String N)
{
 
    // Stores count of even digits
    int even = 0;
 
    // Stores count of odd digits
    int odd = 0;
 
    // Iterate over the digits of N
    for (int it : N.toCharArray())
    {
 
        // If current digit is even
        if ((it - '0') % 2 == 0)
        {
 
            // Update even
            even++;
        }
 
        // Otherwise
        else
        {
 
            // Update odd
            odd++;
        }
    }
 
    // Base conditions
    if (odd == 0 || odd == 1)
    {
        System.out.print("Not Possible"
            + "\n");
    }
 
    else
    {
 
        // Stores count of digits required to be
        // removed to make N odd and the sum of
        // digits of N even
        int ans = 0;
 
        // Iterate over the digits of N
        for (int it : N.toCharArray())
        {
 
            // If current digit is even
            if ((it - '0') % 2 == 0)
            {
 
                // Update ans
                ans++;
            }
 
            // Otherwise,
            else
            {
 
                // Update ans
                ans = 0;
            }
        }
 
        // If count of odd digits is odd
        if (odd % 2 != 0)
        {
 
            // Update ans
            ans++;
        }
 
        // Finally print the ans
        System.out.print(ans +"\n");
    }
}
 
// Driver code
public static void main(String[] args)
{
 
    // Input String
    String N = "12345";
 
    // Function call
    minOperations(N);
}
}
 
// This code is contributed by shikhasingrajput.

Python3

# Python implementation of the above approach
 
# Function to find minimum count of digits
# required to be remove to make N odd and
# the sum of digits of N even
def minOperations(N):
   
    # Stores count of even digits
    even = 0;
 
    # Stores count of odd digits
    odd = 0;
 
    # Iterate over the digits of N
    for it in  N:
 
        # If current digit is even
        if (int(ord(it) - ord('0')) % 2 == 0):
 
            # Update even
            even += 1;
 
        # Otherwise
        else:
 
            # Update odd
            odd += 1;
 
    # Base conditions
    if (odd == 0 or odd == 1):
        print("Not Possible" + "");
 
    else:
 
        # Stores count of digits required to be
        # removed to make N odd and the sum of
        # digits of N even
        ans = 0;
 
        # Iterate over the digits of N
        for it in N:
 
            # If current digit is even
            if (int(ord(it) - ord('0')) % 2 == 0):
 
                # Update ans
                ans += 1;
 
            # Otherwise,
            else:
 
                # Update ans
                ans = 0;
 
        # If count of odd digits is odd
        if (odd % 2 != 0):
           
            # Update ans
            ans += 1;
 
        # Finally print the ans
        print(ans, end=" ");
 
# Driver code
if __name__ == '__main__':
   
    # Input String
    N = "12345";
 
    # Function call
    minOperations(N);
 
# This code is contributed by shikhasingrajput

C#

// C# implementation of the above approach
using System;
class GFG
{
 
// Function to find minimum count of digits
// required to be remove to make N odd and
// the sum of digits of N even
static void minOperations(String N)
{
 
    // Stores count of even digits
    int even = 0;
 
    // Stores count of odd digits
    int odd = 0;
 
    // Iterate over the digits of N
    foreach (int it in N.ToCharArray())
    {
 
        // If current digit is even
        if ((it - '0') % 2 == 0)
        {
 
            // Update even
            even++;
        }
 
        // Otherwise
        else
        {
 
            // Update odd
            odd++;
        }
    }
 
    // Base conditions
    if (odd == 0 || odd == 1)
    {
        Console.Write("Not Possible"
            + "\n");
    }
    else
    {
 
        // Stores count of digits required to be
        // removed to make N odd and the sum of
        // digits of N even
        int ans = 0;
 
        // Iterate over the digits of N
        foreach (int it in N.ToCharArray())
        {
 
            // If current digit is even
            if ((it - '0') % 2 == 0)
            {
 
                // Update ans
                ans++;
            }
 
            // Otherwise,
            else
            {
 
                // Update ans
                ans = 0;
            }
        }
 
        // If count of odd digits is odd
        if (odd % 2 != 0)
        {
 
            // Update ans
            ans++;
        }
 
        // Finally print the ans
        Console.Write(ans +"\n");
    }
}
 
// Driver code
public static void Main(String[] args)
{
 
    // Input String
    String N = "12345";
 
    // Function call
    minOperations(N);
}
}
 
// This code is contributed by shikhasingrajput

Javascript

 
// Javascript implementation of the above approach
 
// Function to find minimum count of digits
// required to be remove to make N odd and
// the sum of digits of N even
function minOperations(N)
{
 
    // Stores count of even digits
    var even = 0;
 
    // Stores count of odd digits
    var odd = 0;
 
    // Iterate over the digits of N
    for (var it =0; it<N.length; it++) {
 
        // If current digit is even
        if ((N[it] - '0') % 2 == 0) {
 
            // Update even
            even++;
        }
 
        // Otherwise
        else {
 
            // Update odd
            odd++;
        }
    }
 
    // Base conditions
    if (odd == 0 || odd == 1) {
        document.write( "Not Possible"
             + "<br>");
    }
 
    else {
 
        // Stores count of digits required to be
        // removed to make N odd and the sum of
        // digits of N even
        var ans = 0;
 
        // Iterate over the digits of N
        for (var it =0; it<N.length; it++){
 
            // If current digit is even
            if ((N[it] - '0') % 2 == 0) {
 
                // Update ans
                ans++;
            }
 
            // Otherwise,
            else {
 
                // Update ans
                ans = 0;
            }
        }
 
        // If count of odd digits is odd
        if (odd % 2) {
 
            // Update ans
            ans++;
        }
 
        // Finally print the ans
        document.write( ans );
    }
}
 
// Driver code
 
// Input string
var N = "12345";
 
// Function call
minOperations(N);
 
 

输出：

1

时间复杂度： O(log ₁₀ (N))
辅助空间： O(1)