goorm 최댓값, 전기요금, 등차 또는 등비 수열

최댓값

# -*- coding: utf-8 -*-
# UTF-8 encoding when using korean
n = int(input())
a = input().split(' ')
max = int(a[0])
idx = 0
for i in range(n):
	if(int(a[i])>max):
		max = int(a[i])
		idx = i
print(max, idx+1)

 

전기요금

# -*- coding: utf-8 -*-
# UTF-8 encoding when using korean
n = int(input())
if(n<100):
	n = n * (5 / 1000)
elif(100<=n and n<200):
	n = n * (7 / 1000)
elif(200<=n and n<300):
	n = n * (9 / 1000)
elif(300<=n):
	n = n * (1 / 100)
print(format(n, ".2f"))

 

등차 또는 등비 수열

#include <iostream>
using namespace std;
int main() {
	int n1,n2,n3,n4;
	cin >> n1>>n2>>n3>>n4;
	if(n2*2==n1+n3 && n3*2 == n2+n4){
		int d = n2 - n1;
		cout << n4+d;
	}
	if(n2 * n2== n1*n3 && n3 * n3 == n2*n4){
		int r  = n2 / n1;
		cout << n4 * r;
	}
	return 0;
}