Maximum subsequence sum such that no three are consecutive

In this tutorial, we will be discussing a program to find maximum subsequence sum such that no three are consecutive.

For this we will be provided with a series of positive integers. Our task is to find the maximum sum without taking in their consecutive positive integers in the sum value.

Example

 Live Demo

#include <bits/stdc++.h>
using namespace std;
//returning maximum subsequence without involving
//three consecutive numbers
int maxSumWO3Consec(int arr[], int n) {
   int sum[n]; if (n >= 1) sum[0] = arr[0];
   if (n >= 2) sum[1] = arr[0] + arr[1];
   if (n > 2) sum[2] = max(sum[1], max(arr[1] + arr[2], arr[0] + arr[2]));
   for (int i = 3; i < n; i++)
      sum[i] = max(max(sum[i - 1], sum[i - 2] + arr[i]), arr[i] + arr[i - 1] + sum[i - 3]);
   return sum[n - 1];
}
int main() {
   int arr[] = { 100, 1000 };
   int n = sizeof(arr) / sizeof(arr[0]);
   cout << maxSumWO3Consec(arr, n);
   return 0;
}

Output

1100