SWEA 1986 지그재그 숫자

1 개요

SWEA 1986 지그재그 숫자

• SW Expert Academy 1986번 문제
• SWEA D2

2 C++

#include <iostream>
using namespace std;
int main() {
	int T;
	scanf("%d", &T);
	int N;
	for(int tc=1; tc<=T; tc++) {
		scanf("%d", &N);
		int sum = 0;
		for(int i=1; i<=N; i++) {
			if( i%2 == 0 ) sum -= i;
			else sum += i;
		}
		printf("#%d %d\n", tc, sum);
	}
}

3 Java

import java.util.Scanner;
class Solution {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();
        for( int t=1; t<=T; t++ ) {
            int n = sc.nextInt();
            int sum = 0;
            for( int i=1; i<=n; i++ ) {
                sum += ( (i%2==0) ? -1 : 1 ) * i;
            }
            System.out.format("#%d %d\n", t, sum);
        }
    }
}

4 Python

#kcy
k = int(input())
for i in range(1, k+1):
    n = int(input())
    sum = 0
    for j in range(1, n+1):
        if j % 2== 0:
            sum = sum - j
        else:
            sum = sum + j
    print("#%d" %i, sum)

T = int(input())
for tt in range(T):
    n = int(input())
    s = 0
    for j in range(1,n+1):
        if j % 2== 0:
            s -= j
        else:
            s += j
    print( f"#{tt+1}", s)