AtCoder Beginner Contest 170 A Problem "Five Variables" Explanation (C ++, Python, Java)

AtCoder Beginner Contest 170 A I will explain the problem "Five Variables".

Problem URL: https://atcoder.jp/contests/abc170/tasks/abc170_a

Problem summary

Five variables $ x_1, x_2, x_3, x_4, x_5 $ are given. The original variable was $ x_i = i $, but only one was assigned $ 0 $. Now, answer which variable was assigned $ 0 $.

Constraint

-The inputs $ x_1, x_2, x_3, x_4, x_5 $ are possible combinations after being substituted.

Commentary

Solution 1

It is a method to perform conditional branching whether it is $ 0 $ for all values. This allows you to find out which variable has $ 0 $ assigned to it.

Solution 2

Let the sequence of $ x_1, x_2, x_3, x_4, x_5 $ be the sequence $ (X) $. In fact, taking advantage of the fact that the sum of the first five variables is $ 15 $, 15 minus the sum of $ X $ </ b> You can see that is the value of the variable to which $ 0 $ is assigned. Therefore, this should be calculated and output.

Below are examples of solutions in Python3, C ++, and Java. (I used the solution of solution 2)

Example of answer for each language

Example solution in Python3

{A.py}


x = list(map(int,input().split()))
print(15 - sum(x))
Example solution in C ++

{A.cpp}


#include<bits/stdc++.h>
using namespace std;
int main(){
  int ans = 15;
  for (int i = 0; i < 5; i++){
    int x;
    cin >> x;
    ans = ans - x;
  }
  cout << ans << endl;
}

(Don't forget the line breaks !!)

Java answer example

{A.java}


import java.util.Scanner;
public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    int ans = 15;
    for (int i = 0; i < 5; i++){
      int x = scan.nextInt();
      ans = ans - x;
    }
    System.out.println(ans);
  }
}

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