제출 #881452

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
881452		noompty	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	577 ms	138596 KiB

tracks

#include <iostream>
#include <vector>
#include <tuple>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <cmath>
#include <array>
#include <random>
#include <string>
#include <cassert>
#include <climits>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>
using namespace std;
 
#define ll long long
#define f first
#define s second
 
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
 
template<typename A> void __print(const A &x);
template<typename A, typename B> void __print(const pair<A, B> &p);
template<typename... A> void __print(const tuple<A...> &t);
template<typename T> void __print(stack<T> s);
template<typename T> void __print(queue<T> q);
template<typename T, typename... U> void __print(priority_queue<T, U...> q);
 
template<typename A> void __print(const A &x) {
    bool first = true;
    cerr << '{';
    for (const auto &i : x) {
        cerr << (first ? "" : ","), __print(i);
        first = false;
    }
    cerr << '}';
}
 
template<typename A, typename B> void __print(const pair<A, B> &p) {
    cerr << '(';
    __print(p.f);
    cerr << ',';
    __print(p.s);
    cerr << ')';
}
 
template<typename... A> void __print(const tuple<A...> &t) {
    bool first = true;
    cerr << '(';
    apply([&first] (const auto &...args) { ((cerr << (first ? "" : ","), __print(args), first = false), ...); }, t);
    cerr << ')';
}
 
template<typename T> void __print(stack<T> s) {
    vector<T> debugVector;
    while (!s.empty()) {
        T t = s.top();
        debugVector.push_back(t);
        s.pop();
    }
    reverse(debugVector.begin(), debugVector.end());
    __print(debugVector);
}
 
template<typename T> void __print(queue<T> q) {
    vector<T> debugVector;
    while (!q.empty()) {
        T t = q.front();
        debugVector.push_back(t);
        q.pop();
    }
    __print(debugVector);
}
 
template<typename T, typename... U> void __print(priority_queue<T, U...> q) {
    vector<T> debugVector;
    while (!q.empty()) {
        T t = q.top();
        debugVector.push_back(t);
        q.pop();
    }
    __print(debugVector);
}
 
void _print() { cerr << "]\n"; }
 
template <typename Head, typename... Tail> void _print(const Head &H, const Tail &...T) {
    __print(H);
    if (sizeof...(T)) cerr << ", ";
    _print(T...);
}
 
#ifdef DEBUG
	#define D(...) cerr << "Line: " << __LINE__ << " [" << #__VA_ARGS__ << "] = ["; _print(__VA_ARGS__)
#else
	#define D(...)
#endif
 
int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, 1, 0, -1};
 
int h, w, dist[4005][4005], ans;
char grid[4005][4005];
deque<pair<int, int>> q;
 
bool valid(int x, int y) {
    if (x < 0 || x >= h || y < 0 || y >= w) return false;
    if (grid[x][y] == '.') return false;
    return true;
}
 
void bfs(int sr, int sc) {
    fill(&dist[0][0], &dist[0][0] + sizeof(dist) / sizeof(dist[0][0]), 2e9);
    dist[sr][sc] = 1;
    q.push_back({sr, sc});
    while (!q.empty()) {
        int cr = q.front().f, cc = q.front().s;
        q.pop_front();
        for (int i = 0, nr, nc; i < 4; i++) {
            nr = cr + dx[i];
            nc = cc + dy[i];
            if (valid(nr, nc)) {
                if (grid[nr][nc] == grid[cr][cc]) {
                    if (dist[nr][nc] > dist[cr][cc]) {
                        dist[nr][nc] = dist[cr][cc];
                        q.push_front({nr, nc});
                    }
                } else {
                    if (dist[nr][nc] > dist[cr][cc] + 1) {
                        dist[nr][nc] = dist[cr][cc] + 1;
                        q.push_back({nr, nc});
                    }
                }
            }
        }
    }
}
 
int main() {
 
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
    cin >> h >> w;
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            cin >> grid[i][j];
        }
    }
 
    bfs(0, 0);
 
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            if (dist[i][j] < 2e9) {
                ans = max(ans, dist[i][j]);
            }
        }
    }
 
    cout << ans << "\n";
 
}

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