제출 #934581

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
934581		May27_th	Mecho (IOI09_mecho)	C++17	84 / 100	146 ms	7000 KiB

mecho

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;

void World_Final();
void Solve();

int main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    if (fopen(taskname".in", "r")) {
        freopen(taskname".in", "r", stdin);
        freopen(taskname".out", "w", stdout);
    }
    World_Final();
}

void World_Final(){
    int Tests = 1;
    //cin >> Tests;
    while (Tests --) {
        Solve();
    }
}

const int MAXN = 805;
int N, S, bee[MAXN][MAXN], bear[MAXN][MAXN]; char G[MAXN][MAXN];
int dx[4] = {0, 0, 1, -1}, dy[4] = {1, -1, 0, 0};
pair<int, int> st, en;
bool query(int rest){
    memset(bear, -1, sizeof(bear));
    queue<pair<int, int>> q; q.push(st); bear[st.first][st.second] = 0;
    while (!q.empty()) {
        int u, v; tie(u, v) = q.front();
        //cout << u << " " << v << "\n";
        q.pop();
        for (int i = 0; i < 4; i ++) {
            int nu = u + dx[i];
            int nv = v + dy[i];
            if (nu >= 1 && nu <= N && nv >= 1 && nv <= N) {
                if (G[nu][nv] == 'G' && bear[nu][nv] == -1) {
                    int t = (bear[u][v] + 1)/S;
                    if (t < bee[nu][nv] - rest) {
                        bear[nu][nv] = bear[u][v] + 1;
                        q.push(make_pair(nu, nv));
                    }
                }
                if (G[nu][nv] == 'D' && bear[nu][nv] == -1) {
                    bear[nu][nv] = bear[u][v] + 1;
                    q.push(make_pair(nu, nv));
                }
            }
        }
    }
    if (bear[en.first][en.second] != -1) return true;
    return false;

}
void Solve(){
    cin >> N >> S;
    for (int i = 1; i <= N; i ++) {
        for (int j = 1; j <= N; j ++) {
            cin >> G[i][j];
        }
    }

    memset(bee, -1, sizeof(bee)); queue<pair<int, int>> q;
    for (int i = 1; i <= N; i ++) {
        for (int j = 1; j <= N; j ++) {
            if (G[i][j] == 'H') {
                bee[i][j] = 0;
                q.push(make_pair(i, j));
            }
            if (G[i][j] == 'M') st = make_pair(i, j);
            if (G[i][j] == 'D') en = make_pair(i, j);
        }
    }
    while (!q.empty()) {
        int u, v; tie(u, v) = q.front();
        q.pop();
        for (int i = 0; i < 4; i ++) {
            int nu = u + dx[i];
            int nv = v + dy[i];
            if (nu >= 1 && nu <= N && nv >= 1 && nv <= N) {
                if ((G[nu][nv] == 'G' || G[nu][nv] == 'M') && bee[nu][nv] == -1) {
                    bee[nu][nv] = bee[u][v] + 1;
                    q.push(make_pair(nu, nv));
                }
            }
        }
    }
    //cout << bee[en.first][en.second] << "\n";
    //cout << query(2);
    int l = 0, h = N * N;
    while (l <= h) {
        int mid = (l + h) / 2;
        //cout << mid << "\n";
        if (query(mid)) l = mid + 1;
        else h = mid - 1;
    } cout << h;
}

컴파일 시 표준 에러 (stderr) 메시지

mecho.cpp: In function 'int main()':
mecho.cpp:11:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |         freopen(taskname".in", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:12:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         freopen(taskname".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 84 / 100