Submission #1192340

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192340		TroySer	Robots (IOI13_robots)	C++20	100 / 100	1762 ms	24940 KiB

robots

#include <bits/stdc++.h>
#include "robots.h"

using namespace std;
using ll = int;

struct Toy {
    ll ind;
    ll weight;
    ll sz;
};

bool cmpForWeight(const Toy &a, const Toy &b) {
    return a.weight < b.weight;
}
bool cmpForSize(const Toy &a, const Toy &b) {
    return a.sz < b.sz;
}

vector<ll> weakRobots, smallRobots;
vector<Toy> considerWeak, considerSmall;

ll t, a, b;
vector<bool> taken;

bool check(ll atMostTime) {

    priority_queue<pair<ll, ll> > pq;
    taken.clear();
    taken.resize(t, false);

    ll toyRemaining = t;

    ll ind = 0;
    for (ll i = 0; i < a; i++) { // for EACH weak robot, keep taking up to `atMostTime` number of toys
        
        while (ind < t && (taken[considerWeak[ind].ind] || considerWeak[ind].weight < weakRobots[i])) {
            if (!taken[considerWeak[ind].ind]) {
                pq.push({considerWeak[ind].sz, considerWeak[ind].ind});
            }
            ind++;
        }
        
        // can take at most `atMostTime` toys, and deduct 1 toy from the entire collection
        ll timeRemaining = atMostTime;
        while (!pq.empty() && timeRemaining > 0) {

            ll currInd = pq.top().second; 
            pq.pop();

            timeRemaining--; toyRemaining--;
            taken[currInd] = true;

        }

    }

    pq = priority_queue<pair<ll, ll> >();

    ind = 0;
    for (ll i = 0; i < b; i++) { // for EACH small robot, keep taking up to `atMostTime` number of toys
        
        // ofc take toys as needed, if you took it then no need
        while (ind < t && (taken[considerSmall[ind].ind] || considerSmall[ind].sz < smallRobots[i])) {
            if (!taken[considerSmall[ind].ind]) {
                pq.push({considerSmall[ind].weight, considerSmall[ind].ind});
            }
            ind++;
        }
        
        ll timeRemaining = atMostTime;
        while (!pq.empty() && timeRemaining > 0) {

            ll currInd = pq.top().second; 
            pq.pop();

            timeRemaining--; toyRemaining--;
            taken[currInd] = true;

        }

    }

    return (toyRemaining == 0);

}

int putaway(int A, int B, int T, int X[], int Y[], int W[], int S[]) {

    t = T;
    a = A;
    b = B;
    
    weakRobots.resize(A);
    for (ll i = 0; i < A; i++) {
        weakRobots[i] = X[i];
    }
    smallRobots.resize(B);
    for (ll i = 0; i < B; i++) {
        smallRobots[i] = Y[i];
    }

    // sort from worst ==> best robot, we can show na letting worst 
    // robot take the easiest load is always optimal
    sort(weakRobots.begin(), weakRobots.end());
    sort(smallRobots.begin(), smallRobots.end());

    considerWeak.resize(T);
    considerSmall.resize(T);
    for (ll i = 0; i < T; i++) {
        considerWeak[i] = Toy{i, W[i], S[i]};
        considerSmall[i] = Toy{i, W[i], S[i]};
    }

    // same logic as above but focusing on toys
    sort(considerWeak.begin(), considerWeak.end(), cmpForWeight);
    sort(considerSmall.begin(), considerSmall.end(), cmpForSize);

    ll l = 0, r = T + 1;
    while (l < r) {
        ll M = (l + r) / 2;
        if (check(M)) {
            r = M;
        } else {
            l = M + 1;
        }
    }

    return (check(l) ? l : -1);

}

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 25 / 25
• Subtask 4: 37 / 37
• Subtask 5: 10 / 10