C++ :

#include <bits/stdc++.h>
using namespace std;
int main(){
    int n,a[110],i;
    cin>>n;
    for(i = 1;i <= n;i++){
    	cin>>a[i];
	}
	int x = a[2] - a[1];
	double y = a[2] * 1.0 / a[1];
	int dc = 1;
	int db = 1;
	for(i = 3;i <= n;i++){
		if(a[i]-a[i-1] != x){
			dc = 0;
		}
		
		if(a[i] * 1.0 / a[i-1] != y){
			db = 0;
		}
	}
	
	if(dc == 1) cout<<"dengcha";
	else if(db == 1) cout<<"dengbi";
	else cout<<"no";
    return 0;
}

Java :

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num1 = scanner.nextInt();
        int[] count = new int[80];
        int[] a = new int[num1];
        for (int i = 0; i < num1; i++) {
            a[i] = scanner.nextInt();
        }
        for (int i = 0; i < num1 - 2; i++) {
            if(a[i] >= a[i+1]){
                if(a[i] % a[i+1] != a[i+1] % a[i+2] && a[i] - a[i+1] != a[i+1] - a[i+2]){
                    System.out.println("no");
                    break;
                }
            }else if(a[i] < a[i+1]){
                if(a[i+2] % a[i+1] != a[i+1] % a[i] && (a[i] - a[i+1] != a[i+1] - a[i+2])){
                    System.out.println("no");break;
                }
            }
            if(i == num1 - 3){
                if(a[i] - a[i+1] == a[i+1] - a[i+2]) System.out.println("dengcha");
                else if(a[i] >= a[i+1] && a[i] % a[i+1] == a[i+1] % a[i+2]) System.out.println("dengbi");
                else if(a[i] < a[i+1] && a[i+2] % a[i+1] == a[i+1] % a[i]) System.out.println("dengbi");
            }
        }





    }public static void paiXu(int[] a,int length){
        int temp;
        for(int i = 0;i < length - 1;i++){
            for(int k = 0;k < length - i - 1;k++){
                if(a[k] > a[k + 1]){
                    temp = a[k];
                    a[k] = a[k + 1];
                    a[k + 1] = temp;
                }
            }
        }
    } public static void paiXud(int[] a){
        int temp;
        for(int i = 0;i < a.length - 1;i++){
            for(int k = 0;k < a.length - i - 1;k++){
                if(a[k] < a[k + 1]){
                    temp = a[k];
                    a[k] = a[k + 1];
                    a[k + 1] = temp;
                }
            }
        }
    } public static void paiXux(int[] a){
        int temp;
        for(int i = 0;i < a.length - 1;i++){
            for(int k = 0;k < a.length - i - 1;k++){
                if(a[k] > a[k + 1]){
                    temp = a[k];
                    a[k] = a[k + 1];
                    a[k + 1] = temp;
                }
            }
        }
    }

    public static int MAX(int[] a){
        int max = a[0];
        for (int i = 0; i < a.length; i++) {
            if(max < a[i]){
                max = a[i];
            }
        }
        return max;
    }

    public static int MIN(int[] a){
        int min = a[0];
        for (int i = 0; i < a.length; i++) {
            if(min > a[i]){
               min = a[i];
            }
        }
        return min;
    }
    public static int sum(int a){
        int x,s = 0;
        while(a != 0){
            x = a % 10;
            s = s + x;
            a /= 10;
        }
        return s;
    }
    public static boolean isPrime(int a){
        if(a <= 1)return false;
        else
        for(int i = 2;i <= Math.sqrt(a);i++){
            if(a % i == 0)return false;
        }return true;
    }

    public static long qiuYu(long i){
        long a;
        a = i % 10;
        return a;
    }
}

Python :

n=int(input())
a=list(map(int,input().split()))
d1=a[1]-a[0]
d2=a[1]/a[0]
f1=0
f2=0
for i in range(2,n):
    if ((a[i]-a[i-1])!=d1):
        f1=1
    if((a[i]/a[i-1])!=d2):
        f2=1
if(f1==0):
    print("dengcha")
elif(f2==0):
    print("dengbi")
else:
    print("no")