令人惊讶的数字是一个数字N，其表示可以分解为两部分，即a和b ，使得N等于从a到b的整数之和，而a + b = N ，其中‘+’表示串联。
几个惊人的数字是：
15, 27, 429, 1353, 1863, 3388, 3591, 7119..
检查N是否是一个令人惊讶的数字
给定数字N ，任务是检查N是否是一个令人惊讶的数字。如果N是一个惊人的数字，则打印“是”，否则打印“否” 。
例子：
Input: N = 429
Output: Yes
Explanation:
429 = 4 + 5 + 6 …….. + 29, where a = 4, b = 29
and a + b = 429 where + denotes concatenation
Input: N = 28
Output: No
方法：这个想法是运行i和j的两个循环，以找到i之前所有整数的和，直到和等于> =N。如果在任何时间点总和等于N，那么我们还将检查是否i和j的串联等于或不等于N。如果等于，则该数字是一个惊人的数字
下面是上述方法的实现：
C++
// C++ implementation for the
// above approach
#include
using namespace std;
// Function to concatenate
// two integers into one
int concat(int a, int b)
{
// Convert both the integers to string
string s1 = to_string(a);
string s2 = to_string(b);
// Concatenate both strings
string s = s1 + s2;
// Convert the concatenated string
// to integer
int c = stoi(s);
// return the formed integer
return c;
}
// Function to check if N is a
// Astonishing number
bool isAstonishing(int n)
{
// Loop to find sum of all integers
// from i till the sum becomes >= n
for (int i = 1; i < n; i++) {
// variable to store
// sum of all integers
// from i to j and
// check if sum and
// concatenation equals n or not
int sum = 0;
for (int j = i; j < n; j++) {
sum += j;
if (sum == n) {
// finding concatenation
// of i and j
int concatenation
= concat(i, j);
// condition for
// Astonishing number
if (concatenation == n) {
return true;
}
}
}
}
return false;
}
// Driver Code
int main()
{
// Given Number
int n = 429;
// Function Call
if (isAstonishing(n))
cout << "Yes";
else
cout << "No";
return 0;
} Java
// Java implementation for the
// above approach
import java.io.*;
class GFG{
// Function to concatenate
// two integers into one
static int concat(int a, int b)
{
// Convert both the integers to String
String s1 = Integer.toString(a);
String s2 = Integer.toString(b);
// Concatenate both Strings
String s = s1 + s2;
// Convert the concatenated String
// to integer
int c = Integer.parseInt(s);
// return the formed integer
return c;
}
// Function to check if N is a
// Astonishing number
static boolean isAstonishing(int n)
{
// Loop to find sum of all integers
// from i till the sum becomes >= n
for (int i = 1; i < n; i++)
{
// variable to store
// sum of all integers
// from i to j and
// check if sum and
// concatenation equals n or not
int sum = 0;
for (int j = i; j < n; j++)
{
sum += j;
if (sum == n)
{
// finding concatenation
// of i and j
int concatenation = concat(i, j);
// condition for
// Astonishing number
if (concatenation == n)
{
return true;
}
}
}
}
return false;
}
// Driver Code
public static void main (String[] args)
{
// Given Number
int n = 429;
// Function Call
if (isAstonishing(n))
System.out.println("Yes");
else
System.out.println("No");
}
}
// This code is contributed by shubhamsingh10Python3
# Python3 implementation for the
# above approach
# Function to concatenate
# two integers into one
def concat(a, b):
# Convert both the integers to string
s1 = str(a)
s2 = str(b)
# Concatenate both strings
s = s1 + s2
# Convert the concatenated string
# to integer
c = int(s)
# return the formed integer
return c
# Function to check if N is a
# Astonishing number
def isAstonishing(n):
# Loop to find sum of all integers
# from i till the sum becomes >= n
for i in range(n):
# variable to store
# sum of all integers
# from i to j and
# check if sum and
# concatenation equals n or not
sum = 0
for j in range(i, n):
sum += j
if (sum == n):
# finding concatenation
# of i and j
concatenation = concat(i, j)
# condition for
# Astonishing number
if (concatenation == n):
return True
return False
# Driver Code
# Given Number
n = 429
# Function Call
if (isAstonishing(n)):
print('Yes')
else:
print('No')
# This code is contributed by YatinC#
// C# implementation for the
// above approach
using System;
class GFG{
// Function to concatenate
// two integers into one
static int concat(int a, int b)
{
// Convert both the integers to String
String s1 = a.ToString();
String s2 = b.ToString();
// Concatenate both Strings
String s = s1 + s2;
// Convert the concatenated String
// to integer
int c = Int32.Parse(s);
// return the formed integer
return c;
}
// Function to check if N is a
// Astonishing number
static bool isAstonishing(int n)
{
// Loop to find sum of all integers
// from i till the sum becomes >= n
for (int i = 1; i < n; i++)
{
// variable to store
// sum of all integers
// from i to j and
// check if sum and
// concatenation equals n or not
int sum = 0;
for (int j = i; j < n; j++)
{
sum += j;
if (sum == n)
{
// finding concatenation
// of i and j
int concatenation = concat(i, j);
// condition for
// Astonishing number
if (concatenation == n)
{
return true;
}
}
}
}
return false;
}
// Driver Code
public static void Main(String[] args)
{
// Given Number
int n = 429;
// Function Call
if (isAstonishing(n))
Console.WriteLine("Yes");
else
Console.WriteLine("No");
}
}
// This code is contributed by 29AjayKumar输出：
Yes
参考： https : //oeis.org/A186074