Second_largest.cpp

/*
   * कर्मणये वाधिकारस्ते मां फलेषु कदाचन ।
   * मां कर्मफलहेतुर्भू: मांते संङगोस्त्वकर्मणि ॥
*/

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

#define bug(...)       __f (#__VA_ARGS__, __VA_ARGS__)

template <typename Arg1>
void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << endl; }
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
    const char* comma = strchr(names + 1, ',');
    cout.write(names, comma - names) << " : " << arg1 << " | "; __f(comma + 1, args...);
}

/*
    * Given an array Arr of size N, print second largest element from an array.
*/
void solve() {
    int n; cin >> n;
    int arr[n];
    for (int i = 0; i < n; i++) cin >> arr[i];

    int first = 0, second = -1;
    for (int i = 1; i < n; i++) {
        if (arr[i] > arr[first]) {
            second = first;
            first = i;
        }
        else if (arr[i] < arr[first]) {
            if (second == -1 || arr[second] < arr[i]) {
                second = i;
            }
        }
    }

    if (second == -1)
        cout << -1;
    else
        cout << arr[second] << " ";
}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

#ifndef ONLINE_JUDGE
    freopen("/home/aman/Desktop/30 Days of Code/input.txt", "r", stdin);
    freopen("/home/aman/Desktop/30 Days of Code/output.txt", "w", stdout);
#endif

    clock_t z = clock();

    int t = 1;
    cin >> t;
    while (t--) solve();

    cerr << "Run Time : " << ((double)(clock() - z) / CLOCKS_PER_SEC) << endl;

    return 0;
}