Submission #893832

#	Time	Username	Problem	Language	Result	Execution time	Memory
893832		kigash	Divide and conquer (IZhO14_divide)	C++17	100 / 100	142 ms	11732 KiB

divide

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

// #pragma comment(linker, "/stack:200000000")
// #pragma GCC optimize("Ofast")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")

using ll = long long;
using ld = long double;
#define pb push_back
#define ff first
#define ss second
#define sz(x) (ll)(x).size()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

void freopen(string s) { freopen((s+".in").c_str(), "r", stdin); freopen((s+".out").c_str(), "w", stdout); }
void IOIGold2024_InshAllah() { ios_base::sync_with_stdio(false); cin.tie(NULL); }
ll binmul(ll a, ll b, ll c) { ll res = 0; while(b) { if(b&1) (res += a) %= c; (a += a) %= c; b >>= 1; } return res; }
ll binpow(ll a, ll b, ll c) { ll res = 1; while(b) { if(b&1) (res *= a) %= c; (a *= a) %= c; b >>= 1; } return res; }
template<typename T> T gcd(T a, T b) { if(b==0) return a; return gcd(b, a%b); }
template<typename T> T lcm(T a, T b) { return a/gcd(a, b)*b; }
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ld rnd() { return rng()%INT_MAX*1.0/INT_MAX; }

const ll inf = 1e18+7, MX = LLONG_MAX, MN = LLONG_MIN;
const ll mod = 1e9+7, N = 3e5+5;
ll x[N], g[N], d[N], mx[N];

void kigash() {
    // x[i]-x[j] <= d[i]-d[j-1] && g[i]-g[j-1] is max
    // x[i]-d[i] <= x[j]-d[j-1]
    ll n;
    cin>>n;
    for(ll i=1; i<=n; i++) {
        cin>>x[i]>>g[i]>>d[i];
        g[i] += g[i-1], d[i] += d[i-1];
    }
    ll l = 0, r = 1e15, ans = -1;
    while(l<=r) {
        ll mid = l+(r-l)/2, ok = 0;
        for(ll i=1; i<=n; i++) {
            mx[i] = max(mx[i-1], x[i]-d[i-1]);
            ll tl = 0, tr = i-1, pos = -1;
            while(tl<=tr) {
                ll tm = tl+(tr-tl)/2;
                if(g[i]-g[tm]>=mid) pos = tm, tl = tm+1;
                else tr = tm-1;
            }
            if(pos==-1) continue;
            if(x[i]-d[i]<=mx[pos+1]) {
                ok = 1;
                break;
            }
        }
        if(ok) ans = mid, l = mid+1;
        else r = mid-1;
    }
    cout<<ans<<"\n";
    return;
}

signed main(/*Kigash Amir*/) {
    // freopen("divide");
    IOIGold2024_InshAllah();
    ll tt = 1;
    // cin>>tt;
    for(ll i=1; i<=tt; i++) {
        kigash();
    }
}

Compilation message (stderr)

divide.cpp: In function 'void freopen(std::string)':
divide.cpp:17:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 | void freopen(string s) { freopen((s+".in").c_str(), "r", stdin); freopen((s+".out").c_str(), "w", stdout); }
      |                          ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
divide.cpp:17:73: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 | void freopen(string s) { freopen((s+".in").c_str(), "r", stdin); freopen((s+".out").c_str(), "w", stdout); }
      |                                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52