将元素数组连接成单个元素
给定一个由N个整数组成的数组arr[] ,任务是打印通过连接数组元素获得的单个整数值。
例子:
Input: arr[] = {1, 23, 345}
Output: 12345
Input: arr[] = {123, 45, 6, 78}
Output: 12345678
方法:可以根据以下观察解决给定的问题:
- Considering X and Y as the two integer values to be joined. And also considering the length of the integer Y as l.
- Then two integers X and Y can be joined together as following:
- X×10l +Y
请按照以下步骤解决问题:
- 初始化一个变量,比如ans为0,以存储结果值。
- 使用变量i遍历数组arr[] ,然后在每次迭代中将ans乘以10的整数arr[i]中数字的计数的幂,并将ans递增arr[i]。
- 最后,经过上述步骤,打印ans中得到的答案。
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 integer value
// obtained by joining array elements
// together
int ConcatenateArr(int arr[], int N)
{
// Stores the resulting integer value
int ans = arr[0];
// Traverse the array arr[]
for (int i = 1; i < N; i++) {
// Stores the count of digits of
// arr[i]
int l = floor(log10(arr[i]) + 1);
// Update ans
ans = ans * pow(10, l);
// Increment ans by arr[i]
ans += arr[i];
}
// Return the ans
return ans;
}
// Driver Code
int main()
{
// Input
int arr[] = { 1, 23, 456 };
int N = sizeof(arr) / sizeof(arr[0]);
// Function call
cout << ConcatenateArr(arr, N);
return 0;
}
Java
// Java program for the above approach
import java.util.*;
class GFG{
// Function to find the integer value
// obtained by joining array elements
// together
static int ConcatenateArr(int[] arr, int N)
{
// Stores the resulting integer value
int ans = arr[0];
// Traverse the array arr[]
for(int i = 1; i < N; i++)
{
// Stores the count of digits of
// arr[i]
int l = (int)Math.floor(Math.log10(arr[i]) + 1);
// Update ans
ans = ans * (int)Math.pow(10, l);
// Increment ans by arr[i]
ans += arr[i];
}
// Return the ans
return ans;
}
// Driver Code
public static void main(String args[])
{
// Input
int arr[] = { 1, 23, 456 };
int N = arr.length;
// Function call
System.out.println(ConcatenateArr(arr, N));
}
}
// This code is contributed by avijitmondal1998
Python3
# Python3 program for the above approach
import math
# Function to find the integer value
# obtained by joining array elements
# together
def ConcatenateArr(arr, N):
# Stores the resulting integer value
ans = arr[0]
# Traverse the array arr[]
for i in range(1, N):
# Stores the count of digits of
# arr[i]
l = math.floor(math.log10(arr[i]) + 1)
# Update ans
ans = ans * math.pow(10, l)
# Increment ans by arr[i]
ans += arr[i]
# Return the ans
return int( ans)
# Driver Code
if __name__ == "__main__":
# Input
arr = [1, 23, 456]
N = len(arr)
# Function call
print(ConcatenateArr(arr, N))
# This code is contributed by ukasp.
C#
// C# program for the above approach
using System;
class GFG{
// Function to find the integer value
// obtained by joining array elements
// together
static int ConcatenateArr(int[] arr, int N)
{
// Stores the resulting integer value
int ans = arr[0];
// Traverse the array arr[]
for(int i = 1; i < N; i++)
{
// Stores the count of digits of
// arr[i]
int l = (int)Math.Floor(Math.Log10(arr[i]) + 1);
// Update ans
ans = ans * (int)Math.Pow(10, l);
// Increment ans by arr[i]
ans += arr[i];
}
// Return the ans
return ans;
}
// Driver Code
public static void Main()
{
// Input
int[] arr = { 1, 23, 456 };
int N = arr.Length;
// Function call
Console.Write(ConcatenateArr(arr, N));
}
}
// This code is contributed by sanjoy_62.
Javascript
输出
123456
时间复杂度: O(N*log(M)),其中 M 是数组的最大元素。
辅助空间: O(1)