제출 #1120716

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1120716		coolboy19521	Tracks in the Snow (BOI13_tracks)	C++17	86.88 / 100	2074 ms	106156 KiB

tracks

#pragma GCC optimize("Ofast")
#include"bits/stdc++.h"
using namespace std;
 
const short mxN = 4001;
 
int cl[mxN][mxN];
short g[mxN][mxN];
short H, W;
 
bool legal(short i, short j) {
    return 0 <= i && 0 <= j && i < H && j < W && 2 != g[i][j];
}
 
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> H >> W;
 
    for (int i = 0; i < H; i ++) {
        for (int j = 0; j < W; j ++) {
            char c;
            cin >> c;
            if ('F' == c) {
                g[i][j] = 1;
            } else if ('.' == c) {
                g[i][j] = 2;
            }
        }
    }
 
    priority_queue<tuple<int,short,short>> pq;
    pq.emplace(-1, 0, 0);
    cl[0][0] = -1;
 
    short dx[] = {0, 0, 1, -1};
    short dy[] = {1, -1, 0, 0};
 
    while (!pq.empty()) {
        auto [c, i, j] = pq.top();
        pq.pop();
        for (int k = 0; k < 4; k ++) {
            short l = i + dx[k];
            short o = j + dy[k];
            if (legal(l, o) && 0 == cl[l][o]) {
                if (g[l][o] == g[i][j]) {
                    cl[l][o] = c;
                    pq.emplace(c, l, o);
                } else {
                    cl[l][o] = c - 1;
                    pq.emplace(c - 1, l, o);
                }
            }
        }
        if (pq.empty()) {
            cout << -c << endl;
        }
    }
}

• Subtask 1: 30 / 30
• Subtask 2: 56.875 / 70