Submission #1135883

#	Time	Username	Problem	Language	Result	Execution time	Memory
1135883		Thanhs	Strange Device (APIO19_strange_device)	C++20	100 / 100	300 ms	17040 KiB

strange_device

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

#define name "TENBAI"
#define fi first
#define se second
#define int long long
#define endl '\n'
#define setmin(x, y) x = min((x), (y))
#define setmax(x, y) x = max((x), (y))
#define sqr(x) ((x) * (x))

mt19937 hdp(chrono::high_resolution_clock::now().time_since_epoch().count());
int rand(int l, int r){return l + ((hdp() % (r - l + 1)) + r - l + 1) % (r - l + 1);}

const int inf = 1e18 + 1;

vector<pair<int, int>> v;
int n, a, b, c, ans;

void solve()
{
    cin >> n >> a >> b;
    int g = __gcd(a, b + 1);
    a /= g;
    if (inf / a < b)
        c = inf;
    else
        c = a * b;
    while (n--)
    {
        int l, r;
        cin >> l >> r;
        if (l / c == r / c)
            v.emplace_back(l % c, r % c);
        else if (l / c == r / c - 1)
            v.emplace_back(l % c, c - 1), v.emplace_back(0, r % c);
        else
        {
            cout << c;
            return;
        }
    }
    sort(v.begin(), v.end());
    // for (auto t : v)
    //     cout << t.fi << ' ' << t.se << endl;
    int l = v[0].fi, r = v[0].se;
    for (auto t : v)
    {
        if (t.fi > r)
        {
            ans += r - l + 1;
            l = t.fi, r = t.se;
        }
        else
            setmax(r, t.se);
    }
    ans += r - l + 1;
    cout << ans;
}

signed main()
{
    if (fopen("in.txt", "r")) 
    {
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
    }
    else if (fopen(name".inp", "r"))
    {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int tc = 1; 
    // cin >> tc;
    while (tc--)
        solve();
}

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:66:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |         freopen("in.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
strange_device.cpp:67:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         freopen("out.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
strange_device.cpp:71:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
strange_device.cpp:72:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20
• Subtask 8: 30 / 30