Submission #446609

# Submission time Handle Problem Language Result Execution time Memory
446609 2021-07-22T17:29:32 Z JerryLiu06 Mecho (IOI09_mecho) C++17
100 / 100
200 ms 6424 KB
#include <bits/stdc++.h>
 
using namespace std;
 
using ll = long long;
using ld = long double;
using db = double;
using str = string;
 
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
 
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>;
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vpd = vector<pd>;
 
#define mp make_pair
#define f first
#define s second
 
#define sz(x) (int)(x).size()
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define sor(x) sort(all(x))
#define rsz resize
#define ins insert 
#define ft front()
#define bk back()
#define pb push_back
#define pf push_front
 
#define lb lower_bound
#define ub upper_bound
 
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define R0F(i, a) ROF(i, 0, a)
#define EACH(a, x) for (auto& a : x)
 
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); }
ll fdiv(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }
 
template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
 
template<class T> void remDup(vector<T>& v) { sor(v); v.erase(unique(all(v)), v.end()); }
 
const int MOD = 1e9 + 7;
const int MX = 810;
const ll INF = 1e18;

const int DIR[4][2] = { {1, 0}, {0, 1}, {-1, 0}, {0, -1} };

int N, S; char G[MX][MX]; int SX, SY, EX, EY;

int distToHive[MX][MX], distToStart[MX][MX];

bool valid(int X, int Y) { return X >= 1 && X <= N && Y >= 1 && Y <= N; }

bool valid(int tim) {
    memset(distToStart, -1, sizeof distToStart);

    distToStart[SX][SY] = 0; 

    queue<pi> Q; Q.push({SX, SY});

    while (!Q.empty()) {
        pi cur = Q.front(); Q.pop();
        
        if (distToHive[cur.f][cur.s] != -1 && distToStart[cur.f][cur.s] / S + tim >= distToHive[cur.f][cur.s]) {
            continue;
        }

        if (cur.f == EX && cur.s == EY) return true;

        F0R(i, 4) {
            int nx = cur.f + DIR[i][0];
            int ny = cur.s + DIR[i][1];

            if (!valid(nx, ny)) continue;

            if (G[nx][ny] != 'T' && distToStart[nx][ny] == -1) {
                distToStart[nx][ny] = distToStart[cur.f][cur.s] + 1;

                Q.push({nx, ny});
            }
        }
    }
    return false;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);

    cin >> N >> S; queue<pi> Q; memset(distToHive, -1, sizeof distToHive);
    
    FOR(i, 1, N + 1) FOR(j, 1, N + 1) {
        char C; cin >> C; if (C == 'M') { SX = i, SY = j; } if (C == 'D') { EX = i, EY = j; }

        if (C == 'H') { Q.push({i, j}); distToHive[i][j] = 0; } G[i][j] = C;
    }
    while (!Q.empty()) {
        pi cur = Q.front(); Q.pop();

        F0R(i, 4) {
            int nx = cur.f + DIR[i][0];
            int ny = cur.s + DIR[i][1];

            if (!valid(nx, ny)) continue; 

            if (distToHive[nx][ny] == -1 && G[nx][ny] != 'T' && G[nx][ny] != 'D') {
                distToHive[nx][ny] = distToHive[cur.f][cur.s] + 1;
                
                Q.push({nx, ny});
            }
        }
    }
    int low = 0; int high = N * N; int res = -1;

    while (low <= high) {
        int mid = (low + high) / 2;

        if (valid(mid)) {
            low = mid + 1; res = mid;
        }
        else {
            high = mid - 1;
        }
    }
    cout << res;
}
# Verdict Execution time Memory Grader output
1 Correct 3 ms 5452 KB Output is correct
2 Correct 3 ms 5452 KB Output is correct
3 Correct 3 ms 5452 KB Output is correct
4 Correct 4 ms 5452 KB Output is correct
5 Correct 3 ms 5452 KB Output is correct
6 Correct 3 ms 5452 KB Output is correct
7 Correct 94 ms 6204 KB Output is correct
8 Correct 3 ms 5452 KB Output is correct
9 Correct 3 ms 5452 KB Output is correct
10 Correct 3 ms 5452 KB Output is correct
11 Correct 3 ms 5452 KB Output is correct
12 Correct 4 ms 5452 KB Output is correct
13 Correct 5 ms 5452 KB Output is correct
14 Correct 4 ms 5452 KB Output is correct
15 Correct 3 ms 5452 KB Output is correct
16 Correct 3 ms 5452 KB Output is correct
17 Correct 3 ms 5452 KB Output is correct
18 Correct 3 ms 5452 KB Output is correct
19 Correct 3 ms 5452 KB Output is correct
20 Correct 3 ms 5452 KB Output is correct
21 Correct 3 ms 5452 KB Output is correct
22 Correct 4 ms 5452 KB Output is correct
23 Correct 4 ms 5452 KB Output is correct
24 Correct 4 ms 5452 KB Output is correct
25 Correct 4 ms 5452 KB Output is correct
26 Correct 4 ms 5452 KB Output is correct
27 Correct 4 ms 5452 KB Output is correct
28 Correct 4 ms 5508 KB Output is correct
29 Correct 4 ms 5508 KB Output is correct
30 Correct 4 ms 5512 KB Output is correct
31 Correct 4 ms 5452 KB Output is correct
32 Correct 4 ms 5452 KB Output is correct
33 Correct 9 ms 5708 KB Output is correct
34 Correct 8 ms 5708 KB Output is correct
35 Correct 25 ms 5736 KB Output is correct
36 Correct 9 ms 5776 KB Output is correct
37 Correct 9 ms 5772 KB Output is correct
38 Correct 31 ms 5780 KB Output is correct
39 Correct 10 ms 5808 KB Output is correct
40 Correct 10 ms 5708 KB Output is correct
41 Correct 40 ms 5808 KB Output is correct
42 Correct 11 ms 5852 KB Output is correct
43 Correct 12 ms 5836 KB Output is correct
44 Correct 52 ms 5836 KB Output is correct
45 Correct 13 ms 5848 KB Output is correct
46 Correct 13 ms 5888 KB Output is correct
47 Correct 57 ms 5876 KB Output is correct
48 Correct 14 ms 5940 KB Output is correct
49 Correct 14 ms 5836 KB Output is correct
50 Correct 69 ms 5928 KB Output is correct
51 Correct 17 ms 5964 KB Output is correct
52 Correct 16 ms 5940 KB Output is correct
53 Correct 89 ms 5976 KB Output is correct
54 Correct 20 ms 5964 KB Output is correct
55 Correct 18 ms 5900 KB Output is correct
56 Correct 101 ms 6000 KB Output is correct
57 Correct 23 ms 5948 KB Output is correct
58 Correct 21 ms 5964 KB Output is correct
59 Correct 119 ms 5948 KB Output is correct
60 Correct 23 ms 6088 KB Output is correct
61 Correct 23 ms 6092 KB Output is correct
62 Correct 136 ms 6076 KB Output is correct
63 Correct 108 ms 6080 KB Output is correct
64 Correct 200 ms 6092 KB Output is correct
65 Correct 160 ms 5964 KB Output is correct
66 Correct 130 ms 6076 KB Output is correct
67 Correct 118 ms 6072 KB Output is correct
68 Correct 52 ms 6084 KB Output is correct
69 Correct 52 ms 6084 KB Output is correct
70 Correct 41 ms 5988 KB Output is correct
71 Correct 46 ms 6024 KB Output is correct
72 Correct 36 ms 6088 KB Output is correct
73 Correct 39 ms 6272 KB Output is correct
74 Correct 65 ms 6356 KB Output is correct
75 Correct 81 ms 6244 KB Output is correct
76 Correct 68 ms 6344 KB Output is correct
77 Correct 72 ms 6368 KB Output is correct
78 Correct 93 ms 6320 KB Output is correct
79 Correct 57 ms 6332 KB Output is correct
80 Correct 74 ms 6212 KB Output is correct
81 Correct 84 ms 6424 KB Output is correct
82 Correct 72 ms 6284 KB Output is correct
83 Correct 90 ms 6252 KB Output is correct
84 Correct 77 ms 6220 KB Output is correct
85 Correct 87 ms 6300 KB Output is correct
86 Correct 90 ms 6188 KB Output is correct
87 Correct 85 ms 6344 KB Output is correct
88 Correct 92 ms 6212 KB Output is correct
89 Correct 91 ms 6356 KB Output is correct
90 Correct 92 ms 6340 KB Output is correct
91 Correct 92 ms 6232 KB Output is correct
92 Correct 101 ms 6240 KB Output is correct