Dado un entero positivo, encuentre el número más grande que podría generarse intercambiando solo dos dígitos como máximo una vez.
Ejemplos:
Input: 2736 Output : 7236 Explanation: If we swap the number 2 and the number 7 then the generated number would be the largest number. Input : 432 Output : 432 Explanation: Here, no swap is required. The given number is already largest.
Enfoque 1 (Probando cada par):
Convertimos el número en una string. Para cada dígito del número, intercambiaremos posiciones (i, j) y lo almacenaremos como verificación temporal si la temperatura es mayor que el número. En caso afirmativo, vuelva a cambiar para restaurar el número original.
C++
// code to find largest number with
// given conditions.
#include <bits/stdc++.h>
using namespace std;
// function to find the largest number
// with given conditions.
int largestNum(int num)
{
// converting the number to the string
string num_in_str = to_string(num);
string temp = num_in_str;
// swapping each digit
for (int i = 0; i < num_in_str.size(); i++) {
for (int j = i + 1; j < num_in_str.size(); j++) {
// Swapping and checking for the larger
swap(num_in_str[i], num_in_str[j]);
if (stoi(num_in_str) > stoi(temp))
temp = num_in_str;
// Reverting the changes
swap(num_in_str[i], num_in_str[j]);
}
}
return stoi(temp);
}
// driver function
int main()
{
int num = 432;
cout << largestNum(num) << endl;
num = 2736;
cout << largestNum(num) << endl;
num = 4596;
cout << largestNum(num) << endl;
return 0;
}
Java
// Java code to find largest number
// with given conditions.
public class LargestNumber {
static String swap(String str, int i, int j)
{
char ch[] = str.toCharArray();
char temp = ch[i];
ch[i] = ch[j];
ch[j] = temp;
String c = String.valueOf(ch);
return c;
}
// function to find the largest number
// with given conditions.
static int largestNum(int num)
{
// converting the number to the string
String num_in_str = "" + num;
String temp = num_in_str;
// swapping each digit
for (int i = 0; i < num_in_str.length(); i++) {
for (int j = i + 1; j < num_in_str.length();
j++) {
// Swapping and checking for the larger
num_in_str = swap(num_in_str, i, j);
if (temp.compareTo(num_in_str) < 0)
temp = num_in_str;
// Reverting the changes
num_in_str = swap(num_in_str, i, j);
}
}
return Integer.parseInt(temp);
}
// Driver code
public static void main(String[] s)
{
int num = 423;
System.out.println(largestNum(num));
num = 2736;
System.out.println(largestNum(num));
num = 4596;
System.out.println(largestNum(num));
}
}
// This code is contributed by Prerena Saini
Python3
# python3 code to find the largest
# number with given conditions.
# function to find the largest number
def largestNum(num):
# converting the number to the list
num_to_str = list(str(num))
temp = num_to_str[:]
# swapping each digit and check for
# the largest number
for i in range(len(num_to_str)):
for j in range(i + 1, len(num_to_str)):
// Swapping current pair
num_to_str[i], num_to_str[j] = num_to_str[j], num_to_str[i]
if num_to_str > temp:
temp = num_to_str[:]
# Reverting above change before next iteration
num_to_str[i], num_to_str[j] = num_to_str[j], num_to_str[i]
# returning the largest number.
return int("".join(temp))
# main function
def main():
A = int(432)
print(largestNum(A))
A = int(2736)
print(largestNum(A))
A = int(4596)
print(largestNum(A))
# calling main function
if __name__=="__main__":
main()
C#
// C# code to find largest number
// with given conditions.
using System;
public class LargestNumber {
static String swap(String str, int i, int j)
{
char[] ch = str.ToCharArray();
char temp = ch[i];
ch[i] = ch[j];
ch[j] = temp;
String c = String.Join("", ch);
return c;
}
// function to find the largest number
// with given conditions.
static int largestNum(int num)
{
// converting the number to the string
String num_in_str = "" + num;
String temp = num_in_str;
// swapping each digit
for (int i = 0; i < num_in_str.Length; i++) {
for (int j = i + 1; j < num_in_str.Length;
j++) {
// Swapping and checking for the larger
num_in_str = swap(num_in_str, i, j);
if (temp.CompareTo(num_in_str) < 0)
temp = num_in_str;
// Reverting the changes
num_in_str = swap(num_in_str, i, j);
}
}
return Convert.ToInt32(temp);
}
// Driver code
public static void Main(String[] s)
{
int num = 423;
Console.WriteLine(largestNum(num));
num = 2736;
Console.WriteLine(largestNum(num));
num = 4596;
Console.WriteLine(largestNum(num));
}
}
// This code is contributed by 29AjayKumar
Javascript
<script>
// JavaScript code to find largest number with
// given conditions.
// function to find the largest number
// with given conditions.
function largestNum(num)
{
// converting the number to the string
var num_in_str = (num.toString().split(''));
var temp = JSON.parse(JSON.stringify(num_in_str));
// swapping each digit
for (var i = 0; i < num_in_str.length; i++) {
for (var j = i + 1; j < num_in_str.length; j++)
{
// Swapping and checking for the larger
[num_in_str[i], num_in_str[j]] =
[num_in_str[j], num_in_str[i]];
if (parseInt(num_in_str.join('')) >
parseInt(temp.join('')))
temp =
JSON.parse(JSON.stringify(num_in_str));
// Reverting the changes
[num_in_str[i], num_in_str[j]] =
[num_in_str[j], num_in_str[i]];
}
}
return parseInt(temp.join(''));
}
// driver function
var num = 432;
document.write( largestNum(num) + "<br>");
num = 2736;
document.write( largestNum(num) + "<br>");
num = 4596;
document.write( largestNum(num) + "<br>");
</script>
Producción:
432 7236 9546
Enfoque 2 (eficiente):
escanearemos el número desde la dirección hacia atrás. En el escaneo, si el dígito i es el más grande con diferencia, guárdelo junto con su índice o si el dígito actual es más pequeño que el dígito más grande registrado con diferencia, este dígito y el dígito más grande son los más adecuados para el intercambio.
A continuación se muestra la implementación del enfoque anterior.
C++
// code to find largest number with
// given conditions.
#include <bits/stdc++.h>
using namespace std;
// function to find the largest number
// with given conditions.
int largestNum(int num)
{
int max_digit = -1;
int max_digit_indx = -1;
int l_indx = -1;
int r_indx = -1;
// converting the number to string
string num_in_str = to_string(num);
for (int i = num_in_str.size() - 1; i >= 0; i--) {
// current digit is the largest by far
if (num_in_str[i] > max_digit) {
max_digit = num_in_str[i];
max_digit_indx = i;
continue;
}
// best digit for swap if there is no more
// such situation on the left side
if (num_in_str[i] < max_digit) {
l_indx = i;
r_indx = max_digit_indx;
}
}
// check for is number already in order
if (l_indx == -1)
return num;
swap(num_in_str[l_indx], num_in_str[r_indx]);
return stoi(num_in_str);
}
// driver function
int main()
{
int num = 789;
cout << largestNum(num) << endl;
num = 49658;
cout << largestNum(num) << endl;
num = 2135;
cout << largestNum(num) << endl;
return 0;
}
Java
// Java to find largest number with
// given conditions.
class GFG {
// function to find the largest number
// with given conditions.
static int largestNum(int num)
{
int max_digit = -1;
int max_digit_indx = -1;
int l_indx = -1;
int r_indx = 1;
// converting the number to string
String num_in_str = String.valueOf(num);
for (int i = num_in_str.length() - 1; i >= 0; i--) {
// current digit is the largest by far
if (num_in_str.charAt(r_indx) > max_digit) {
max_digit = num_in_str.charAt(i);
max_digit_indx = i;
continue;
}
// best digit for swap if there is no more
// such situation on the left side
if (num_in_str.charAt(i) < max_digit) {
l_indx = i;
r_indx = max_digit_indx;
}
}
// check for is number already in order
if (l_indx == -1)
return num;
num_in_str = swap(num_in_str, l_indx, r_indx);
return Integer.parseInt(num_in_str);
}
static String swap(String arr, int i, int j)
{
char temp[] = arr.toCharArray();
char c = temp[i];
temp[i] = temp[j];
temp[j] = c;
return String.valueOf(temp);
}
// Driver code
public static void main(String[] args)
{
int num = 789;
System.out.println(largestNum(num));
num = 49658;
System.out.println(largestNum(num));
num = 2135;
System.out.println(largestNum(num));
}
}
// This code contributed by Rajput-Ji
Python3
# Python3 to find largest number with
# given conditions.
# Function to find the largest number
# with given conditions.
def largestNum(num):
max_digit = -1
max_digit_indx = -1
l_indx = -1
r_indx = 1
# converting the number to string
num_in_str = list(str(num))
for i in range(len(num_in_str) - 1, -1, -1):
# current digit is the largest by far
if int(num_in_str[i]) > int(max_digit):
max_digit = num_in_str[i]
max_digit_indx = i
continue
# best digit for swap if there is no more
# such situation on the left side
if int(num_in_str[i]) < int(max_digit):
l_indx = i
r_indx = max_digit_indx
# check for is number already in order
if l_indx == -1:
return num
num_in_str[l_indx], num_in_str[r_indx] = \
num_in_str[r_indx], num_in_str[l_indx]
return int(''.join(num_in_str))
# Driver Code
num = 789
print(largestNum(num))
num = 49658
print(largestNum(num))
num = 2135
print(largestNum(num))
# This code is contributed by Gowtham Yuvaraj
C#
// C# to find largest number with
// given conditions.
using System;
class GFG {
// function to find the largest number
// with given conditions.
static int largestNum(int num)
{
int max_digit = -1;
int max_digit_indx = -1;
int l_indx = -1;
int r_indx = 1;
// converting the number to string
String num_in_str = String.Join("", num);
for (int i = num_in_str.Length - 1; i >= 0; i--) {
// current digit is the largest by far
if (num_in_str[r_indx] > max_digit) {
max_digit = num_in_str[i];
max_digit_indx = i;
continue;
}
// best digit for swap if there is no more
// such situation on the left side
if (num_in_str[i] < max_digit) {
l_indx = i;
r_indx = max_digit_indx;
}
}
// check for is number already in order
if (l_indx == -1)
return num;
num_in_str = swap(num_in_str, l_indx, r_indx);
return int.Parse(num_in_str);
}
static String swap(String arr, int i, int j)
{
char[] temp = arr.ToCharArray();
char c = temp[i];
temp[i] = temp[j];
temp[j] = c;
return String.Join("", temp);
}
// Driver code
public static void Main(String[] args)
{
int num = 789;
Console.WriteLine(largestNum(num));
num = 49658;
Console.WriteLine(largestNum(num));
num = 2135;
Console.WriteLine(largestNum(num));
}
}
/* This code contributed by PrinciRaj1992 */
Producción:
987 94658 5132
Publicación traducida automáticamente
Artículo escrito por Abhishek Sharma 44 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA