Buying Order (Easy)

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

int maxItems(int N, const vector<int>& B) {
    vector<int> itemsWithOne, itemsWithZero;

    // Separate items based on B
    if(B[N-1]==1){
    for (int i = N - 1; i >= 0; i--) {
        if (B[i] == 1)
            itemsWithOne.push_back(i + 1); // Item numbers are 1-based
    }
    for (int i = 0; i < N; i++) {
        if (B[i] == 0) {
            itemsWithZero.push_back(i + 1);
        }
    }

    int totalItems = 0;

    if (!itemsWithZero.empty() && !itemsWithOne.empty()) {
        // Check if itemsWithZero[0] > itemsWithOne.back()
        if (itemsWithZero.front() > itemsWithOne.back()) {
            totalItems = 2 * itemsWithZero.size() + 2 * (itemsWithOne.size() - 1) + 1;
        } else {
            totalItems = (2 * (itemsWithZero.size() - 1) + 1) + (2 * (itemsWithOne.size() - 1) + 1);
        }
    } else {
        // If one of the vectors is empty
        if (!itemsWithZero.empty()) {
            totalItems = 2 * itemsWithZero.size()-1;
        } else if (!itemsWithOne.empty()) {
            totalItems = 2 * itemsWithOne.size()-1;
        }
    }

    return totalItems;
    }
    
    
    
    else
    {
        for (int i = N - 1; i >= 0; i--) {
        if (B[i] == 1)
            itemsWithOne.push_back(i + 1); // Item numbers are 1-based
    }
    for (int i = 0; i < N; i++) {
        if (B[i] == 0) {
            itemsWithZero.push_back(i + 1);
        }
    }

    int totalItems = 0;

    if (!itemsWithZero.empty() && !itemsWithOne.empty()) {
        // Check if itemsWithZero[0] > itemsWithOne.back()
        if (itemsWithZero.back() > itemsWithOne.front()) {
            totalItems = 2 *( itemsWithZero.size()-1)+1 + 2 * (itemsWithOne.size());
        } else {
            totalItems = (2 * (itemsWithZero.size() - 1) + 1) + (2 * (itemsWithOne.size() - 1) + 1);
        }
    } else {
        // If one of the vectors is empty
        if (!itemsWithZero.empty()) {
            totalItems = 2 * itemsWithZero.size()-1;
        } else if (!itemsWithOne.empty()) {
            totalItems = 2 * itemsWithOne.size()-1;
        }
    }

    return totalItems;
    }
}

int main() {
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        vector<int> v(n);
        for (int i = 0; i < n; i++) {
            cin >> v[i];
        }
        cout << maxItems(n, v) << endl;
    }
}