Can't find a range of maximum product subarray - c++

Question

I'm solving Maximum Product Subarray problem on C++. My code finds only a max.product of subarray, but not a range.
I found some explanation here - https://www.geeksforgeeks.org/maximum-product-subarray/ and used the code. How could I find the range(Left index, Right index) of subarray that gives me maximum product? (I found some similar posts here, but all of them on java, and i can't understand them properly)
#include<bits/stdc++.h>
#include <stdio.h>
using namespace std;
int min(int x, int y) {
return (x < y) ? x : y;
}
int max(int x, int y) {
return (x > y) ? x : y;
}
int solve(int a[], int n){
int maxend = 0, minend = 0;
int maxans = 0;
for (int i = 1; i <= n; i++){
int temp = maxend;
maxend = max(a[i], max(a[i] * maxend, a[i] * minend));
minend = min(a[i], min(a[i] * temp, a[i] * minend));
maxans = max(maxans, maxend);
}
return maxans;
}
int main(void){
int n, a[10000];
cin >> n;
for(int i=1; i<=n; i++){
cin >> a[i];
}
cout << solve(a, n);
return 0;
}

Answer 1

If all you need is the range information, you can keep track of the indices where maxans variable changed. That would indicate to you where the maximum product comes from, which would be the right endpoint of the range. Then, after you compute the maxans, you can basically go left until you get the maximum product, at which point you will have found the left interval.
The following implementation can serve as a demonstration.
int solve(int a[], int n){
int maxend = 0, minend = 0;
int maxans = 0;
int max_r = -1;
for (int i = 1; i <= n; i++){
int temp = maxend;
maxend = max(a[i], max(a[i] * maxend, a[i] * minend));
minend = min(a[i], min(a[i] * temp, a[i] * minend));
if(maxans < maxend){
maxans = maxend;
max_r = i;
}
}
int max_l = max_r;
for(int i=1; i < maxans; max_l--){
i = i * a[max_l];
}
//At this point you have the range [max_l, max_r] that yield maxans as the product
return maxans;
}