Submission #853642

#	Time	Username	Problem	Language	Result	Execution time	Memory
853642		dranjohn	Robot Contest (IOI23_robot)	C++17	30 / 100	107 ms	7052 KiB

robot

#include "robot.h"
#include <bits/stdc++.h>
using namespace std;
// https://oj.uz/problem/view/IOI23_robot

constexpr int MAXS = 8;

/*
2 right
3 down
4 blocked
5 right skip
6 down skip
7 left skip
8 up skip
*/

bool empty(int x) {
    return x >= 0 && x != 4;
}

bool neighbor(int left, int down, int right, int up, vector<int> xs) {
    for (int x : xs) {
        if (left == x || down == x || right == x || up == x)
            return true;
    }
    return false;
}

pair<char, int> dir(int self, int left, int down, int right, int up) {
    // done
    if (right == -2 && down == -2) {
        if (left == 2) return { 'W', 1 };
        if (up == 3) return { 'N', 1 };

        if (left == 5) return { 'W', 1 };
        if (up == 6) return { 'N', 1 };
    }
    if (left == -2 && up == -2) {
        if (neighbor(left, down, right, up, { 1 })) return { 'T', 1 };

        if (empty(right) && self < 2) return { 'E', 2 };
        if (empty(down) && self < 3) return { 'S', 3 };

        if (right >= 0 && self < 5) return { 'E', 5 };
        if (down >= 0 && self < 6) return { 'S', 6 };

        return { 'T', 19 };
    }

    if (left == 1 || down == 1 || right == 1 || up == 1) {
        if (left == 2) return { 'W', 1 };
        if (up == 3) return { 'N', 1 };

        if (right == 7) return { 'E', 1 };
        if (down == 8) return { 'S', 1 };
        if (left == 5) return { 'W', 1 };
        if (up == 6) return { 'N', 1 };
    }
    
    bool second_phase = neighbor(left, down, right, up, { 5, 6, 7, 8 });

    if (empty(right) && !second_phase && self < 2) return { 'E', 2 };
    if (empty(down) && !second_phase && self < 3) return { 'S', 3 };

    if (right >= 0 && right < 5 && second_phase && self < 5) return { 'E', 5 };
    if (down >= 0 && down < 5 && second_phase && self < 6) return { 'S', 6 };
    if (left >= 0 && left < 5 && second_phase && self < 7) return { 'W', 7 };
    if (up >= 0 && up < 5 && second_phase && self < 8) return { 'N', 8 };

    if (left == 2) return { 'W', 4 };
    if (up == 3) return { 'N', 4 };

    if (down == 8) return { 'S', 0 };
    if (right == 7) return { 'E', 0 };
    if (up == 6) return { 'N', 0 };
    if (left == 5) return { 'W', 0 };
    
    // unknown state
    return { 'T', 19 };
}

void program_pulibot() {
    vector<int> states;
    for (int i = -2; i <= MAXS; ++i) states.push_back(i);
    
    for (int l : states)
    for (int d : states)
    for (int r : states)
    for (int u : states)
    for (int s : states) {
        char nd;
        int ns;
        tie(nd, ns) = dir(s, l, d, r, u);
    
        set_instruction({ s, l, d, r, u }, ns, nd);
    }
}

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 5 / 10
• Subtask 3: 9 / 18
• Subtask 4: 10 / 20
• Subtask 5: 0 / 46