Geek-onacci Number.cpp

/*
Geek created a random series and given a name geek-onacci series. 
Given four integers A, B, C, N. A, B, C represents the first three numbers of geek-onacci series. 
Find the Nth number of the series. The nth number of geek-onacci series is a sum of the last 
three numbers (summation of N-1th, N-2th, and N-3th geek-onacci numbers)

Input:
1. The first line of the input contains a single integer T denoting the number of test cases. 
The description of T test cases follows.
2. The first line of each test case contains four space-separated integers A, B, C, and N.

Output: For each test case, print Nth geek-onacci number

Constraints:
1. 1 <= T <= 3
2. 1 <= A, B, C <= 100
3. 4 <= N <= 10

Example:
Input:
3
1 3 2 4
1 3 2 5
1 3 2 6

Output:
6
11
19
*/



#include<bits/stdc++.h>
using namespace std;


int solve(int a, int b, int c, int n) {
    if (n == 1) return a;
    else if (n == 2) return b;
    else if (n == 3) return c;
    
    int next = a + b + c;
    
    return solve(b, c, next, n - 1);
    
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    
    int t;
    cin >> t;
    
    while (t--) {
        int a, b, c, n;
        cin >> a >> b >> c >> n;
        
        cout << solve(a, b, c, n) << "\n";
    }



return 0;
}