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Submission #491455

# Submission time Handle Problem Language Result Execution time Memory
491455 2021-12-02T14:11:17 Z XII Mecho (IOI09_mecho) C++17
100 / 100
 169 ms 10704 KB 
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define fi first
#define se second
#define mp make_pair
#define eb emplace_back
#define ALL(x) (x).begin(), (x).end()

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define FORU(i, a, b) for(int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)

#define IOS cin.tie(0)->sync_with_stdio(false);
#define PROB "IOI09_mecho"
void Fi(){
    if(fopen(PROB".inp", "r")){
        freopen(PROB".inp", "r", stdin);
        freopen(PROB".out", "w", stdout);
    }
}

const int INF = 1e9;
const int N = 800 + 1;
int n, spd;
int a[N][N];
using pi = pair<int, int>;
pi S, E;
queue<pi> qe;

int d[N][N];
const int dx[] = {0, 0, -1, +1};
const int dy[] = {-1, +1, 0, 0};

void bfsBee(){
    while(!qe.empty()){
        auto [x, y] = qe.front(); qe.pop();
        FOR(direc, 0, 4){
            int i = x + dx[direc];
            int j = y + dy[direc];
            if(i < 1 || n < i || j < 1 || n < j) continue;
            if(a[i][j] == 1 && d[i][j] == -1){
                d[i][j] = d[x][y] + 1;
                qe.emplace(i, j);
            }
        }
    }
}

pi D[N][N];
bool bfsMecho(const int &T){
    FORU(i, 1, n) FORU(j, 1, n) D[i][j] = {INF, INF};
    qe.emplace(S); D[S.fi][S.se] = {T, 0};
    while(!qe.empty()){
        auto [x, y] = qe.front(); qe.pop();
//        cout << x << " " << y << " " << D[x][y].fi << " " << D[x][y].se << "\n";
        FOR(direc, 0, 4){
            int i = x + dx[direc];
            int j = y + dy[direc];
            if(i < 1 || n < i || j < 1 || n < j) continue;
            if(a[i][j] && D[i][j].fi == INF){
                D[i][j] = D[x][y];
                if(++D[i][j].se >= spd){
                    ++D[i][j].fi;
                    D[i][j].se = 0;
                }
                if(a[i][j] == 2){
                    while(!qe.empty()) qe.pop();
                    return true;
                }
                if(D[i][j].fi < d[i][j]){
                    qe.emplace(i, j);
                }
            }
        }
    }
    return false;
}

int main(){
    IOS;
    Fi();
    cin >> n >> spd;
    memset(d, -1, sizeof(d));
    FORU(i, 1, n){
        string s; cin >> s;
        FORU(j, 1, n){
            switch(s[j - 1]){
                case 'T': a[i][j] = 0; break;
                case 'G': a[i][j] = 1; break;
                case 'M': a[i][j] = 1; S = {i, j}; break;
                case 'D': a[i][j] = 2; E = {i, j}; break;
                case 'H': a[i][j] = 0; qe.emplace(i, j); d[i][j] = 0; break;
            }
        }
    }
    bfsBee();
    int l = 0, r = d[S.fi][S.se] - 1, ans = -1;
    while(l <= r){
        int m = (l + r) / 2;
        if(bfsMecho(m)) l = m + 1, ans = m;
        else r = m - 1;
    }
    cout << ans;
    return 0;
}

Compilation message

mecho.cpp: In function 'void Fi()':
mecho.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen(PROB".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen(PROB".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2764 KB Output is correct
2 Correct 1 ms 2764 KB Output is correct
3 Correct 1 ms 2764 KB Output is correct
4 Correct 1 ms 2764 KB Output is correct
5 Correct 2 ms 2892 KB Output is correct
6 Correct 1 ms 2892 KB Output is correct
7 Correct 106 ms 10444 KB Output is correct
8 Correct 1 ms 2892 KB Output is correct
9 Correct 1 ms 2892 KB Output is correct
10 Correct 1 ms 2892 KB Output is correct
11 Correct 1 ms 2892 KB Output is correct
12 Correct 1 ms 3276 KB Output is correct
13 Correct 2 ms 3148 KB Output is correct
14 Correct 2 ms 3276 KB Output is correct
15 Correct 1 ms 2892 KB Output is correct
16 Correct 2 ms 2892 KB Output is correct
17 Correct 1 ms 3020 KB Output is correct
18 Correct 1 ms 3020 KB Output is correct
19 Correct 1 ms 2980 KB Output is correct
20 Correct 1 ms 3020 KB Output is correct
21 Correct 2 ms 3148 KB Output is correct
22 Correct 2 ms 3020 KB Output is correct
23 Correct 2 ms 3148 KB Output is correct
24 Correct 2 ms 3124 KB Output is correct
25 Correct 1 ms 3276 KB Output is correct
26 Correct 2 ms 3276 KB Output is correct
27 Correct 2 ms 3276 KB Output is correct
28 Correct 2 ms 3276 KB Output is correct
29 Correct 1 ms 3276 KB Output is correct
30 Correct 2 ms 3276 KB Output is correct
31 Correct 2 ms 3404 KB Output is correct
32 Correct 1 ms 3404 KB Output is correct
33 Correct 6 ms 6092 KB Output is correct
34 Correct 6 ms 6092 KB Output is correct
35 Correct 19 ms 6092 KB Output is correct
36 Correct 8 ms 6604 KB Output is correct
37 Correct 7 ms 6608 KB Output is correct
38 Correct 24 ms 6616 KB Output is correct
39 Correct 8 ms 6988 KB Output is correct
40 Correct 9 ms 7012 KB Output is correct
41 Correct 31 ms 6988 KB Output is correct
42 Correct 9 ms 7556 KB Output is correct
43 Correct 14 ms 7468 KB Output is correct
44 Correct 44 ms 7500 KB Output is correct
45 Correct 11 ms 8012 KB Output is correct
46 Correct 13 ms 8040 KB Output is correct
47 Correct 53 ms 8028 KB Output is correct
48 Correct 14 ms 8396 KB Output is correct
49 Correct 16 ms 8396 KB Output is correct
50 Correct 56 ms 8500 KB Output is correct
51 Correct 17 ms 8868 KB Output is correct
52 Correct 16 ms 8908 KB Output is correct
53 Correct 84 ms 8980 KB Output is correct
54 Correct 17 ms 9448 KB Output is correct
55 Correct 19 ms 9360 KB Output is correct
56 Correct 104 ms 9408 KB Output is correct
57 Correct 21 ms 9932 KB Output is correct
58 Correct 20 ms 9920 KB Output is correct
59 Correct 98 ms 9912 KB Output is correct
60 Correct 22 ms 10316 KB Output is correct
61 Correct 24 ms 10360 KB Output is correct
62 Correct 139 ms 10368 KB Output is correct
63 Correct 110 ms 10360 KB Output is correct
64 Correct 168 ms 10308 KB Output is correct
65 Correct 169 ms 10368 KB Output is correct
66 Correct 126 ms 10364 KB Output is correct
67 Correct 115 ms 10360 KB Output is correct
68 Correct 51 ms 10388 KB Output is correct
69 Correct 49 ms 10488 KB Output is correct
70 Correct 45 ms 10368 KB Output is correct
71 Correct 38 ms 10380 KB Output is correct
72 Correct 37 ms 10316 KB Output is correct
73 Correct 39 ms 10564 KB Output is correct
74 Correct 59 ms 10572 KB Output is correct
75 Correct 57 ms 10636 KB Output is correct
76 Correct 62 ms 10640 KB Output is correct
77 Correct 64 ms 10636 KB Output is correct
78 Correct 66 ms 10564 KB Output is correct
79 Correct 53 ms 10612 KB Output is correct
80 Correct 62 ms 10704 KB Output is correct
81 Correct 59 ms 10572 KB Output is correct
82 Correct 57 ms 10580 KB Output is correct
83 Correct 79 ms 10572 KB Output is correct
84 Correct 71 ms 10576 KB Output is correct
85 Correct 78 ms 10572 KB Output is correct
86 Correct 79 ms 10564 KB Output is correct
87 Correct 68 ms 10564 KB Output is correct
88 Correct 112 ms 10524 KB Output is correct
89 Correct 85 ms 10640 KB Output is correct
90 Correct 84 ms 10500 KB Output is correct
91 Correct 83 ms 10512 KB Output is correct
92 Correct 93 ms 10436 KB Output is correct