Submission #773345

# Submission time Handle Problem Language Result Execution time Memory
773345 2023-07-04T23:36:22 Z sz1218 Mecho (IOI09_mecho) C++14
100 / 100
130 ms 6300 KB
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef pair<int, pi> pii;
typedef pair<ll, ll> pl;
typedef pair<ll, pl> pll;
typedef vector<int> vi;

#define pb push_back
#define f first
#define s second

int __i__, __j__;
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}

#define For(i,a,b) for (int i = (a); i < (b); ++i)
#define Fir(i,a) For(i,0,a)
#define Rof(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define Rif(i,a) Rof(i,0,a)

const int NN = 805, mod = 1e9 + 7, INF = 0x3f3f3f3f;
int n, S, dism[NN][NN], disb[NN][NN], mx, my, ex, ey, dir[4][2]{{0, 1}, {0, -1}, {-1, 0}, {1, 0}}, ans;char g[NN][NN];
queue<pi> qb;

bool check(int x, int y){
    return 1 <= x && x <= n && 1 <= y && y <= n && g[x][y] != 'T';
}

void bfs(){
    while(!qb.empty()){
        auto[ux, uy] = qb.front(); qb.pop();
        For(d, 0, 4){
            int nx = ux + dir[d][0],  ny = uy + dir[d][1];
            if(check(nx, ny) && g[nx][ny] != 'D'){
                if(disb[nx][ny] == INF){
                    disb[nx][ny] = disb[ux][uy] + 1;
                    qb.push({nx, ny});
                }
            }
        }
    }
}

bool escapable(int delay){
    memset(dism, 0x3f, sizeof(dism));
    queue<pi> q; q.push({mx, my});dism[mx][my] = 0;
    if(delay >= disb[mx][my])return false;
    while(!q.empty()){
        auto[x, y] = q.front(); q.pop();
        For(d, 0, 4){
            int nx = x + dir[d][0], ny = y+dir[d][1];
            if(check(nx, ny)){
                if(dism[nx][ny] == INF){
                    if(nx == ex && ny == ey){
                        return true;
                    }
                    if( (dism[x][y]+1)/S < disb[nx][ny] - delay){
                        dism[nx][ny] = dism[x][y] + 1;
                        q.push({nx, ny});
                    }
                }
            }
        }
    }
    return false;
}

int main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    cin >> n >> S;
    memset(disb, 0x3f, sizeof(disb));
    For(i, 1, n+1){
        For(j, 1, n+1){
            cin >> g[i][j];
            if(g[i][j] == 'M'){
                mx = i; my = j;
            }
            if(g[i][j] == 'H'){
                qb.push({i, j}); disb[i][j] = 0;
            }
            if(g[i][j] == 'D'){
                ex = i; ey = j;
            }
        }
    }

    bfs(); disb[ex][ey] = INF;
    int lo = 0, hi = 7e5; ans = -1;
    while(lo <= hi){
        int mid = (lo + hi)/2;
        if(escapable(mid)){
            ans = mid; lo = mid+1;
        }
        else{
            hi = mid-1;
        }
    }

    cout << ans << endl;
    return 0;
}

Compilation message

mecho.cpp: In function 'void bfs()':
mecho.cpp:34:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   34 |         auto[ux, uy] = qb.front(); qb.pop();
      |             ^
mecho.cpp: In function 'bool escapable(int)':
mecho.cpp:52:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   52 |         auto[x, y] = q.front(); q.pop();
      |             ^
# Verdict Execution time Memory Grader output
1 Correct 3 ms 5332 KB Output is correct
2 Correct 3 ms 5332 KB Output is correct
3 Correct 3 ms 5332 KB Output is correct
4 Correct 4 ms 5332 KB Output is correct
5 Correct 3 ms 5332 KB Output is correct
6 Correct 3 ms 5332 KB Output is correct
7 Correct 61 ms 6052 KB Output is correct
8 Correct 4 ms 5332 KB Output is correct
9 Correct 3 ms 5332 KB Output is correct
10 Correct 3 ms 5332 KB Output is correct
11 Correct 3 ms 5332 KB Output is correct
12 Correct 4 ms 5332 KB Output is correct
13 Correct 3 ms 5332 KB Output is correct
14 Correct 3 ms 5332 KB Output is correct
15 Correct 3 ms 5332 KB Output is correct
16 Correct 3 ms 5332 KB Output is correct
17 Correct 3 ms 5332 KB Output is correct
18 Correct 3 ms 5332 KB Output is correct
19 Correct 4 ms 5332 KB Output is correct
20 Correct 4 ms 5332 KB Output is correct
21 Correct 3 ms 5332 KB Output is correct
22 Correct 3 ms 5332 KB Output is correct
23 Correct 4 ms 5332 KB Output is correct
24 Correct 3 ms 5444 KB Output is correct
25 Correct 3 ms 5332 KB Output is correct
26 Correct 3 ms 5332 KB Output is correct
27 Correct 3 ms 5332 KB Output is correct
28 Correct 3 ms 5332 KB Output is correct
29 Correct 3 ms 5460 KB Output is correct
30 Correct 3 ms 5332 KB Output is correct
31 Correct 3 ms 5436 KB Output is correct
32 Correct 3 ms 5460 KB Output is correct
33 Correct 5 ms 5580 KB Output is correct
34 Correct 5 ms 5588 KB Output is correct
35 Correct 19 ms 5588 KB Output is correct
36 Correct 6 ms 5716 KB Output is correct
37 Correct 7 ms 5712 KB Output is correct
38 Correct 26 ms 5696 KB Output is correct
39 Correct 6 ms 5716 KB Output is correct
40 Correct 7 ms 5660 KB Output is correct
41 Correct 27 ms 5716 KB Output is correct
42 Correct 7 ms 5716 KB Output is correct
43 Correct 7 ms 5776 KB Output is correct
44 Correct 31 ms 5700 KB Output is correct
45 Correct 9 ms 5716 KB Output is correct
46 Correct 8 ms 5736 KB Output is correct
47 Correct 48 ms 5816 KB Output is correct
48 Correct 9 ms 5776 KB Output is correct
49 Correct 9 ms 5844 KB Output is correct
50 Correct 46 ms 5860 KB Output is correct
51 Correct 10 ms 5844 KB Output is correct
52 Correct 10 ms 5844 KB Output is correct
53 Correct 51 ms 5844 KB Output is correct
54 Correct 11 ms 5844 KB Output is correct
55 Correct 10 ms 5844 KB Output is correct
56 Correct 63 ms 5940 KB Output is correct
57 Correct 12 ms 5908 KB Output is correct
58 Correct 12 ms 5892 KB Output is correct
59 Correct 72 ms 5980 KB Output is correct
60 Correct 14 ms 5972 KB Output is correct
61 Correct 13 ms 6016 KB Output is correct
62 Correct 83 ms 6020 KB Output is correct
63 Correct 77 ms 6008 KB Output is correct
64 Correct 128 ms 5896 KB Output is correct
65 Correct 130 ms 6008 KB Output is correct
66 Correct 103 ms 5940 KB Output is correct
67 Correct 88 ms 5928 KB Output is correct
68 Correct 36 ms 5956 KB Output is correct
69 Correct 33 ms 6056 KB Output is correct
70 Correct 37 ms 6036 KB Output is correct
71 Correct 29 ms 6060 KB Output is correct
72 Correct 24 ms 5964 KB Output is correct
73 Correct 26 ms 6288 KB Output is correct
74 Correct 44 ms 6300 KB Output is correct
75 Correct 48 ms 6212 KB Output is correct
76 Correct 44 ms 6292 KB Output is correct
77 Correct 47 ms 6228 KB Output is correct
78 Correct 54 ms 6264 KB Output is correct
79 Correct 42 ms 6268 KB Output is correct
80 Correct 46 ms 6188 KB Output is correct
81 Correct 51 ms 6188 KB Output is correct
82 Correct 45 ms 6228 KB Output is correct
83 Correct 55 ms 6220 KB Output is correct
84 Correct 55 ms 6224 KB Output is correct
85 Correct 50 ms 6144 KB Output is correct
86 Correct 58 ms 6228 KB Output is correct
87 Correct 57 ms 6148 KB Output is correct
88 Correct 59 ms 6072 KB Output is correct
89 Correct 59 ms 6168 KB Output is correct
90 Correct 64 ms 6092 KB Output is correct
91 Correct 58 ms 6172 KB Output is correct
92 Correct 58 ms 6096 KB Output is correct