Submission #465142

# Submission time Handle Problem Language Result Execution time Memory
465142 2021-08-15T08:50:20 Z MohamedFaresNebili Mecho (IOI09_mecho) C++14
84 / 100
347 ms 42804 KB
#include <bits/stdc++.h>

using namespace std;

using ll  = long long;
using ld  = long double;
using db  = double;
using ii  = pair<int, int>;
using pl  = pair<ll, ll>;
using vi  = vector<int>;
using vl  = vector<ll>;
using vii = vector<ii>;
using vpl = vector<pl>;

#define mp make_pair
#define pb push_back
#define pp pop_back
#define ff first
#define ss second
#define lb lower_bound
#define ub upper_bound
#define sz(v) ((int)v.size())
#define all(x) (x).begin() , (x).end()
#define FAST ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

ld dist(ld x, ld y, ld a, ld b) { return sqrt((x-a)*(x-a) + (y-b)*(y-b)); }
ll gcd(ll a , ll b){ return b ? gcd(b , a % b) : a ;}
ll lcm(ll a , ll b){ return (a * b) / gcd(a , b);}
ll fact(ll n) { return n > 1?(n * fact(n-1)):1;}
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void IO(string s = "") { if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } }

const int N = 2024;
const int inf = 1e9;
const int MOD = 1e9+7;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up
const int dr[8] = {1,1,0,-1,-1,-1, 0, 1}, dc[8] = {0,1,1, 1, 0,-1,-1,-1};  // S,SE,E,NE,N,NW,W,SW
const long long INF = 1e18;
const double EPS = 1e-9;
const double PI = 3.14159265358979323846;

/** |||||||||||||||||||||||||||||||| SOLUTION |||||||||||||||||||||||||||||||| **/

ll n, m; char grid[N][N]; ll d[N][N];
ll vis[N][N]; ll sx, sy, hx, hy;
bool bfs(ll v)
{
    if(v*m>=d[sx][sy]) return false;
    memset(vis, 0, sizeof(vis)); vis[sx][sy]=1;
    deque<pair<ll, pl>>q; q.pb(mp(v*m, mp(sx, sy)));
    while(!q.empty()) {
        ll w=q.front().ff, a=q.front().ss.ff, b=q.front().ss.ss; q.pop_front();
        if(grid[a][b]=='D') return true;
        for(ll l=0;l<4;l++) {
            ll x=a+nx[l], y=b+ny[l];
            if(x>=0&&x<n&&y>=0&&y<n) {
                if(grid[x][y]=='T'||w+1>=d[x][y]||vis[x][y]) continue;
                q.pb(mp(w+1, mp(x, y))); vis[x][y]=1;
            }
        }
    }
    return false;
}

void solve()
{
    /// JUST KEEP GOING
    cin>>n>>m; deque<pl>q;
    for(ll l=0;l<n;l++) {
        for(ll i=0;i<n;i++) {
            cin>>grid[l][i]; d[l][i]=inf;
            if(grid[l][i]=='H') { d[l][i]=0; q.pb(mp(l, i)); }
            else if(grid[l][i]=='M') { sx=l; sy=i; grid[l][i]=='G'; }
            else if(grid[l][i]=='D') { hx=l; hy=i; }
        }
    }
    while(!q.empty()) {
        ll a=q.front().ff, b=q.front().ss; q.pop_front();
        for(ll l=0;l<4;l++) {
            ll x=a+nx[l], y=b+ny[l];
            if(x>=0&&x<n&&y>=0&&y<n) {
                if(d[x][y]==inf&&grid[x][y]=='G') {
                    d[x][y]=d[a][b]+m; q.push_back(mp(x, y));
                }
            }
        }
    }
    ll lo=-1, hi=n*n*2; d[hx][hy]=n*n*m;
    while(hi-lo>1) {
        ll mid=(lo+hi)/2;
        if(bfs(mid)) { lo=mid; }
        else hi=mid;
    }
    cout<<lo<<'\n';
}

int32_t main()
{

    FAST; /// IO("lasers");
    int t; t=1;
    while(t--) {
        solve();
    }
    return 0;

}

/*** Stuff you should look for :
   * int overflow, array bounds.
   * special cases (n=1?).
   * Observe The Constraints.
   * do smth instead of nothing and stay organized.
   * Reformulate The Problem Into Something More Theoretical.
   * WRITE STUFF DOWN.
   * DON'T GET STUCK ON ONE APPROACH.
   * Don't Spend Too Much Time On The Problem: Move On!
   * If You Don't Fight You Cannot Win.
***/

Compilation message

mecho.cpp: In function 'void solve()':
mecho.cpp:74:62: warning: statement has no effect [-Wunused-value]
   74 |             else if(grid[l][i]=='M') { sx=l; sy=i; grid[l][i]=='G'; }
      |                                                    ~~~~~~~~~~^~~~~
mecho.cpp: In function 'void setIn(std::string)':
mecho.cpp:30:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 | void setIn(string s) { freopen(s.c_str(),"r",stdin); }
      |                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
mecho.cpp: In function 'void setOut(std::string)':
mecho.cpp:31:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 | void setOut(string s) { freopen(s.c_str(),"w",stdout); }
      |                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 32 ms 32332 KB Output is correct
2 Correct 37 ms 32396 KB Output is correct
3 Correct 32 ms 32424 KB Output is correct
4 Correct 36 ms 32428 KB Output is correct
5 Correct 40 ms 32332 KB Output is correct
6 Correct 44 ms 32332 KB Output is correct
7 Correct 241 ms 42440 KB Output is correct
8 Correct 45 ms 32444 KB Output is correct
9 Correct 49 ms 32460 KB Output is correct
10 Correct 49 ms 32460 KB Output is correct
11 Correct 48 ms 32352 KB Output is correct
12 Incorrect 64 ms 32756 KB Output isn't correct
13 Incorrect 60 ms 32692 KB Output isn't correct
14 Correct 63 ms 32716 KB Output is correct
15 Correct 54 ms 32500 KB Output is correct
16 Correct 50 ms 32500 KB Output is correct
17 Correct 53 ms 32492 KB Output is correct
18 Correct 59 ms 32452 KB Output is correct
19 Correct 56 ms 32568 KB Output is correct
20 Correct 52 ms 32572 KB Output is correct
21 Correct 59 ms 32588 KB Output is correct
22 Correct 60 ms 32588 KB Output is correct
23 Correct 64 ms 32688 KB Output is correct
24 Correct 63 ms 32708 KB Output is correct
25 Correct 64 ms 32768 KB Output is correct
26 Correct 64 ms 32780 KB Output is correct
27 Correct 66 ms 32716 KB Output is correct
28 Correct 68 ms 32820 KB Output is correct
29 Correct 67 ms 32844 KB Output is correct
30 Correct 69 ms 32844 KB Output is correct
31 Correct 67 ms 32868 KB Output is correct
32 Correct 69 ms 32880 KB Output is correct
33 Correct 84 ms 35404 KB Output is correct
34 Correct 89 ms 35340 KB Output is correct
35 Correct 121 ms 35448 KB Output is correct
36 Correct 93 ms 35916 KB Output is correct
37 Correct 93 ms 36032 KB Output is correct
38 Correct 126 ms 35976 KB Output is correct
39 Correct 103 ms 36648 KB Output is correct
40 Correct 97 ms 36684 KB Output is correct
41 Correct 150 ms 36672 KB Output is correct
42 Correct 96 ms 37324 KB Output is correct
43 Correct 97 ms 37336 KB Output is correct
44 Correct 175 ms 37344 KB Output is correct
45 Correct 103 ms 37960 KB Output is correct
46 Correct 99 ms 38056 KB Output is correct
47 Correct 176 ms 38072 KB Output is correct
48 Correct 105 ms 38760 KB Output is correct
49 Correct 106 ms 38920 KB Output is correct
50 Correct 213 ms 38808 KB Output is correct
51 Correct 110 ms 39576 KB Output is correct
52 Correct 107 ms 39564 KB Output is correct
53 Correct 224 ms 39652 KB Output is correct
54 Correct 115 ms 40392 KB Output is correct
55 Correct 113 ms 40348 KB Output is correct
56 Correct 252 ms 40508 KB Output is correct
57 Correct 113 ms 41404 KB Output is correct
58 Correct 111 ms 41284 KB Output is correct
59 Correct 279 ms 41248 KB Output is correct
60 Correct 122 ms 42180 KB Output is correct
61 Correct 114 ms 42180 KB Output is correct
62 Correct 312 ms 42120 KB Output is correct
63 Correct 220 ms 42240 KB Output is correct
64 Correct 347 ms 42084 KB Output is correct
65 Correct 279 ms 42168 KB Output is correct
66 Correct 274 ms 42176 KB Output is correct
67 Correct 234 ms 42180 KB Output is correct
68 Correct 154 ms 42228 KB Output is correct
69 Correct 159 ms 42224 KB Output is correct
70 Correct 138 ms 42180 KB Output is correct
71 Correct 154 ms 42168 KB Output is correct
72 Incorrect 140 ms 42228 KB Output isn't correct
73 Incorrect 232 ms 42804 KB Output isn't correct
74 Correct 183 ms 42640 KB Output is correct
75 Correct 205 ms 42724 KB Output is correct
76 Correct 186 ms 42728 KB Output is correct
77 Correct 184 ms 42700 KB Output is correct
78 Correct 217 ms 42572 KB Output is correct
79 Correct 167 ms 42604 KB Output is correct
80 Correct 194 ms 42564 KB Output is correct
81 Correct 199 ms 42616 KB Output is correct
82 Correct 189 ms 42692 KB Output is correct
83 Correct 223 ms 42672 KB Output is correct
84 Correct 207 ms 42584 KB Output is correct
85 Correct 249 ms 42508 KB Output is correct
86 Correct 231 ms 42564 KB Output is correct
87 Correct 217 ms 42544 KB Output is correct
88 Correct 228 ms 42492 KB Output is correct
89 Correct 224 ms 42576 KB Output is correct
90 Correct 238 ms 42440 KB Output is correct
91 Correct 233 ms 42444 KB Output is correct
92 Correct 251 ms 42492 KB Output is correct