1556C - Compressed Bracket Sequence - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#ifdef __linux__
#include "/media/gakshat468/New Volume/CP/algo/debug.h"
#elif _WIN32
#include "D:/CP/algo/debug.h"
#endif
#else
#define debug(...) 42
#endif
#define MOD 1000000007
#define nl <<'\n'
#define display_vec(a) for(auto i:a)cout<<i<<" "; cout <<"\n";
#define sp <<" "<<
#define fast_io ios_base::sync_with_stdio(false); cin.tie(NULL)
#define int long long int
#pragma GCC target("popcnt")

bool solve()
{
    int n;
    cin >> n;
    vector<int> c(n + 1), a(n + 1);
    for (int i = 1;i <= n;i++) {
        cin >> c[i];
        a[i] += a[i - 1] + (2 * (i % 2) - 1) * c[i];
    }
    int ans = 0;
    for (int i = 2;i <= n;i += 2) {
        int minm = a[i - 1] - 1;
        for (int j = i - 1;j >= 1 && minm >= a[i];j -= 2) {
            if (a[j] > minm && a[j - 1] <= minm) {
                ans += minm - max(a[j - 1], a[i]) + 1;
                minm = a[j - 1];
            }
        }
    }

    cout << ans nl;
    return true;
}

signed main()
{
    fast_io;
#ifdef __linux__
    string path = "/media/gakshat468/New Volume/CP/";
#elif _WIN32
    string path = "D:/CP/";
#endif
#ifndef ONLINE_JUDGE
    freopen((path + "input.txt").c_str(), "r", stdin);
    freopen((path + "output.txt").c_str(), "w", stdout);
    freopen((path + "error.txt").c_str(), "w", stderr);
#endif
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
        // cout << (solve() ? "YES\n" : "NO\n");
        // cout << (solve() ? "" : "-1\n");
    }
}