제출 #972931

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
972931		jadai007	Mecho (IOI09_mecho)	C++17	100 / 100	154 ms	7048 KiB

mecho

#include <bits/stdc++.h>

using namespace std;
 
const int MAX_N = 810, INF = 1e9 + 7, d[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
char s[MAX_N][MAX_N];
int bee[MAX_N][MAX_N], bear[MAX_N][MAX_N], sx, sy, ex, ey;
queue<pair<int, int>> q;
 
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int N, S;
    cin >> N >> S;
    for(int i = 1; i <= N; i++) cin >> (s[i] + 1);
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= N; j++) {
            bee[i][j] = INF;
            if(s[i][j] == 'H') {
                bee[i][j] = 0;
                q.emplace(i, j);
            }
            else if(s[i][j] == 'M') sx = i, sy = j;
            else if(s[i][j] == 'D') ex = i, ey = j;
        }    
    }
    while(!q.empty()) {
        int ux = q.front().first, uy = q.front().second; q.pop();
        for(int i = 0; i < 4; i++) {
            int vx = ux + d[i][0], vy = uy + d[i][1];
            if(vx < 1 || vx > N || vy < 1 || vy > N || s[vx][vy] == 'T' || s[vx][vy] == 'D' || bee[vx][vy] != INF) continue;
            bee[vx][vy] = bee[ux][uy] + 1;
            q.emplace(vx, vy);
        }
    }
    int l = 0, r = N * N, ans = -1;
    while(l <= r) {
        int mid = (l + r) / 2;
        for(int i = 1; i <= N; i++) for(int j = 1; j <= N; j++) bear[i][j] = INF;
        if(bee[sx][sy] > mid) {
            q.emplace(sx, sy);
            bear[sx][sy] = 0;
        }
        while(!q.empty()) {
            int ux = q.front().first, uy = q.front().second; q.pop();
            for(int i = 0; i < 4; i++) {
                int vx = ux + d[i][0], vy = uy + d[i][1];
                if(vx < 1 || vx > N || vy < 1 || vy > N || s[vx][vy] == 'T' || bear[vx][vy] != INF) continue;
                if((bear[ux][uy] + 1) / S >= bee[vx][vy] - mid) continue;
                bear[vx][vy] = bear[ux][uy] + 1;
                q.emplace(vx, vy);
            }
        }
        if(bear[ex][ey] == INF) r = mid - 1;
        else{
            l = mid + 1;
            ans = mid;
        }
    }
    cout << ans;
    return 0;
}

• Subtask 1: 100 / 100