Submission #1101372

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101372		jadai007	Mecho (IOI09_mecho)	C++17	23 / 100	134 ms	9236 KiB

mecho

#include<bits/stdc++.h>

using namespace std;

int n, s, disH[1010][1010], dis[1010][1010], xx[] = {0, 0, -1, 1}, xy[] = {-1, 1, 0, 0};
char mp[1010][1010];
queue<tuple<int, int, int>> q;

bool solve(int mid){
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= n; ++j){
            if(mp[i][j] == 'M') q.emplace(i, j, 0), dis[i][j] = 0;
            else dis[i][j] = 1e9;
        }
    }
    while(!q.empty()){
        int x = get<0>(q.front()), y = get<1>(q.front()), w = get<2>(q.front()); q.pop();
        if(dis[x][y] < w || (dis[x][y] + 1) / s >= disH[x][y] - mid) continue;
        if(mp[x][y] == 'D') return true;
        for(int i = 0; i < 4; ++i){
            int nx = x + xx[i];
            int ny = y + xy[i];
            if(nx < 1 || nx > n || ny < 1 || ny > n || mp[nx][ny] == 'T') continue;
            if(dis[nx][ny] > w + 1){
                dis[nx][ny] = w + 1;
                q.emplace(nx, ny, w + 1);
            }
        }
    }
    return false;
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n >> s;
    for(int i = 1; i<=n; ++i) for(int j = 1; j <= n; ++j) cin >> mp[i][j];
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <=n; ++j){
            if(mp[i][j] == 'H') q.emplace(i, j, 0), disH[i][j] = 0;
            else disH[i][j] = 1e9;
        }
    }
    while(!q.empty()){
        int x = get<0>(q.front()), y = get<1>(q.front()), w = get<2>(q.front()); q.pop();
        if(disH[x][y] < w) continue;
        for(int i = 0; i < 4; ++i){
            int nx = x + xx[i];
            int ny = y + xy[i];
            if(nx < 1 || nx > n || ny < 1 || ny > n || mp[nx][ny] == 'T') continue;
            if(disH[nx][ny] > w + 1){
                disH[nx][ny] = w + 1;
                q.emplace(nx, ny, w + 1);
            }
        }   
    }
    int l = 0, r = 1e9, ans = -1;
    while(l <= r){
        int mid = (l + r) >> 1;
        if(solve(mid)) ans = mid, l = mid + 1;
        else r = mid - 1;
    }
    cout << ans;
}

• Subtask 1: 23 / 100