Submission #808967

#	Time	Username	Problem	Language	Result	Execution time	Memory
808967		jakobrs	Wombats (IOI13_wombats)	C++17	37 / 100	20075 ms	17736 KiB

wombats

#include <algorithm>
#include <numeric>
#include <queue>
#include <vector>

#ifndef EVAL
#include <iostream>
#endif

#include "wombats.h"

#define entire(a) std::begin((a)), std::end((a))

std::vector<std::vector<int>> h, v;
int r, c;
void init(int R, int C, int H[5000][200], int V[5000][200]) {
    h.reserve(R);
    v.reserve(R);
    for (int i = 0; i < R; i++) {
        h.emplace_back(entire(H[i]));
        v.emplace_back(entire(V[i]));
    }
    r = R;
    c = C;
}

void changeH(int P, int Q, int W) { h[P][Q] = W; }

void changeV(int P, int Q, int W) { v[P][Q] = W; }

int escape(int V1, int V2) {
    std::vector<int> dist(c, 0);

    dist[V1] = 0;
    for (int i = V1 + 1; i < c; i++) {
        dist[i] = dist[i - 1] + h[0][i - 1];
    }
    for (int i = V1 - 1; i >= 0; i--) {
        dist[i] = dist[i + 1] + h[0][i];
    }

    std::priority_queue<std::pair<int, int>> pq;

    for (int i = 0; i + 1 < r; i++) {
        // phase 1: process vertical segments
        for (int j = 0; j < c; j++) {
            dist[j] += v[i][j];
        }

        // phase 2: process horizontal segments
        while (!pq.empty()) pq.pop();  // whyy is there no pq.clear();
        for (int j = 0; j < c; j++) {
            pq.push({-dist[j], j});
        }
        while (!pq.empty()) {
            auto [d, j] = pq.top();
            pq.pop();
            d = -d;

            if (d > dist[j]) continue;

            if (j > 0 && dist[j - 1] > d + h[i + 1][j - 1]) {
                dist[j - 1] = d + h[i + 1][j - 1];
                pq.push({-dist[j - 1], j - 1});
            }
            if (j + 1 < c && dist[j + 1] > d + h[i + 1][j]) {
                dist[j + 1] = d + h[i + 1][j];
                pq.push({-dist[j + 1], j + 1});
            }
        }
    }

    return dist[V2];
}

Compilation message (stderr)

grader.c: In function 'int main()':
grader.c:15:6: warning: variable 'res' set but not used [-Wunused-but-set-variable]
   15 |  int res;
      |      ^~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 0 / 18
• Subtask 5: 0 / 21
• Subtask 6: 0 / 24