Submission #714499

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
714499	2023-03-24T18:59:30 Z	MuichiroTo	Mecho (IOI09_mecho)	C++14	100 / 100	310 ms	2220 KB

mecho

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h> 
using namespace std;
 
typedef long long ll;
#define int ll
typedef long double ld;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pair<int, int>> vpi;
typedef vector<vector<int>> vvi;

const int mod = 1000000007;

#define FOR(i,e) for(ll i = 0; i < e; i++)
#define FORM(i,s,e) for(ll i = s; i < e; i++)
#define nl "\n"
#define printArr(arr) FOR(abcd, arr.size()){cout<<arr[abcd]<<" ";}cout<<nl;
#define dbg(x) cout<<#x<<" = "<<x<<nl
#define pb push_back
#define pob pop_back
#define fi first
#define se second
#define INF 2e18
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define FOREACH(a,b) for(auto &(a): (b))
#define rev(v) reverse(all(v))
#define cint(n) int n; cin>>n
#define cint2(a,b) int a,b; cin>>a>>b
#define cint3(a,b,c) int a,b,c; cin>>a>>b>>c

int gcdExtended(int a, int b, int *x, int *y)
{
    // Base Case
    if (a == 0)
    {
        *x = 0, *y = 1;
        return b;
    }

    int x1, y1; // To store results of recursive call
    int gcd = gcdExtended(b % a, a, &x1, &y1);

    // Update x and y using results of recursive
    // call
    *x = y1 - (b / a) * x1;
    *y = x1;

    return gcd;
}

// Function to find modulo inverse of a
ll modInverse(ll a, ll m)
{
    int x, y;
    int g = gcdExtended(a, m, &x, &y);
    if (g != 1)
        return 0;
    else
    {
        // m is added to handle negative x
        ll res = (x % m + m) % m;
        return res;
    }
}

ll nCr(int n, int r){
    // remember to commend the ans/=i line in case of modulo
    if(r>n){
        return 0;
    }
    if(r>n-r){
        r = n-r;
    }
    ll ans = 1;
    for(int i = 1; i<=r ; i++){
        ans *= (n-i+1);
     // ans%= mod;
     // ans *= modInverse(i, mod);
     // ans %= mod;

    //   *********** COMMENT ***********
        ans /= i;
    }
 
    return ans;
}
 
ll binpow(ll a, ll b) {
    if (b == 0)
        return 1;
    long long res = binpow(a, b / 2);
    if (b % 2)
        return (res * res)%mod * a % mod;
    else
        return (res * res) %mod;
}

// Segment Tree, lazy and Normal
// struct segTree{
//     int size;
//     vector<int> seg;
//     vector<int> lazy;
//     void init(int n){
//         size = 1;
//         while(size<n) size *= 2;
//         seg.assign(2*size, 0LL);
//         lazy.assign(2*size, 0LL);
//     }
//     void build(vector<int> &arr, int idx, int lx, int rx){
//         if(lx>rx) return;
//         if(lx == rx){
//             if(lx<sz(arr))
//                 seg[idx] = arr[lx];
//             return;
//         }
//         int m = (lx + rx)/2;
//         build(arr, 2*idx+1, lx, m);
//         build(arr, 2*idx+2, m+1, rx);
//         seg[idx] = seg[2*idx+1] + seg[2*idx+2];
//         return;
//     }
//     void build(vector<int> &arr){
//         build(arr, 0, 0, size-1);
//     }
//     void rangeUpdate(int idx, int lx, int rx, int l, int r, int val){
//         if(lazy[idx]!=0){
//             seg[idx] += (rx-lx+1)*lazy[idx];
//             if(lx!=rx){
//                 lazy[2*idx+1] += lazy[idx];
//                 lazy[2*idx+2] += lazy[idx];
//             }
//             lazy[idx] = 0;
//         }
//         if(r<lx || l>rx || lx>rx) return;
//         if(lx>=l && rx<=r){
//             seg[idx] += (rx-lx+1)*val;
//             if(lx!=rx){
//                 lazy[2*idx+1] += val;
//                 lazy[2*idx+2] += val;
//             }
//             return;
//         }
//         int mid = (lx+rx)/2;
//         rangeUpdate(2*idx+1, lx, mid, l, r, val);
//         rangeUpdate(2*idx+1, mid+1, rx, l, r, val);
//         seg[idx] = seg[2*idx+1] + seg[2*idx+2];
//     }
//     void rangeUpdate(int l, int r, int val){
//         rangeUpdate(0, 0, size-1, l, r, val);
//     }
//     int querySumLazy(int idx, int lx, int rx, int l, int r){
//         if(lazy[idx] != 0){
//             seg[idx] += (rx-lx+1)*lazy[idx];
//             if(lx!=rx){
//                 lazy[2*idx+1] += lazy[idx];
//                 lazy[2*idx+2] += lazy[idx];
//             }
//             lazy[idx] = 0;
//         }
//         if(r<lx || l>rx || lx>rx) return 0;
//         if(lx>=l && rx<=r){
//             return seg[idx];
//         }
//         int mid = (lx+rx)/2;
//         return querySumLazy(2*idx+1, lx, mid, l, r) + querySumLazy(2*idx+2,mid+1,rx,l,r);
//     }
//     int querySumLazy(int l, int r){
//         return querySumLazy(0, 0, size-1, l, r);
//     }
//     void set(int target_idx, int v, int idx, int lx, int rx){
//         if(lx==rx){
//             seg[idx] = v;
//             return;
//         }
//         int m = (lx + rx)/2;
//         if(target_idx<=m){
//             set(target_idx, v, 2*idx+1, lx, m);
//         }
//         else{
//             set(target_idx, v, 2*idx+2, m+1, rx);
//         }   
//         seg[idx] = seg[2*idx+1] + seg[2*idx+2];
//         return;
//     }
//     void set(int i, int v){
//         set(i, v, 0, 0, size-1);
//     }
//     int sum(int l, int r, int idx, int lx, int rx){
//         if(rx<l || lx>r) return 0;
//         if(lx>=l && rx<=r) return seg[idx];
//         int m = (lx+rx)/2;
//         int s1 = sum(l, r, 2*idx+1, lx, m);
//         int s2 = sum(l, r, 2*idx+2, m+1, rx);
//         return (s1 + s2);
//     }
//     int sum(int l, int r){
//         return sum(l, r, 0, 0, size-1);
//     }
// };

// z-array is 0 indexed
// vector<int> z_function(string &s) {
//     int n = (int) s.length();
//     vector<int> z(n);
//     for (int i = 1, l = 0, r = 0; i < n; ++i) {
//         if (i <= r)
//             z[i] = min (r - i + 1, z[i - l]);
//         while (i + z[i] < n && s[z[i]] == s[i + z[i]])
//             ++z[i];
//         if (i + z[i] - 1 > r)
//             l = i, r = i + z[i] - 1;
//     }
//     return z;
// }

// PRIME FACTORISATION USING SEIVE  
// #define MAXN 100001
// int spf[MAXN];
// void sieve()
// {
//     spf[1] = 1;
//     for (int i=2; i<MAXN; i++)
//         spf[i] = i;
//     for (int i=4; i<MAXN; i+=2)
//         spf[i] = 2;
//     for (int i=3; i*i<MAXN; i++)
//     {
//         if (spf[i] == i)
//         {
//             for (int j=i*i; j<MAXN; j+=i)
//                 if (spf[j]==j)
//                     spf[j] = i;
//         }
//     }
// }
// void getFactorization(int x, vector<int> &factors)
// {
//     while (x != 1)
//     {
//         factors.push_back(spf[x]);
//         x = x / spf[x];
//     }
// }

// LINEAR SIEVE
// const int N = 10000000;
// vector<int> lp(N+1);
// vector<int> pr;
// void linSv(){
//     for (int i=2; i <= N; ++i) {
//         if (lp[i] == 0) {
//             lp[i] = i;
//             pr.push_back(i);
//         }
//         for (int j = 0; i * pr[j] <= N; ++j) {
//             lp[i * pr[j]] = pr[j];
//             if (pr[j] == lp[i]) {
//                 break;
//             }
//         }
//     }
// }

// LOWEST COMMON ANCESTOR
// N = (n+1) in case of 1 indexed
// resize adj -> preprocess(root) -> LCA
// int N, l;
// vector<vector<int>> adj;
// int timer;
// vector<int> tin, tout;
// vector<vector<int>> up;
// void dfs(int v, int p)
// {
//     tin[v] = ++timer;
//     up[v][0] = p;
//     for (int i = 1; i <= l; ++i)
//         up[v][i] = up[up[v][i-1]][i-1];
//     for (int u : adj[v]) {
//         if (u != p)
//             dfs(u, v);
//     }
//     tout[v] = ++timer;
// }
// bool is_ancestor(int u, int v)
// {
//     return tin[u] <= tin[v] && tout[u] >= tout[v];
// }
// int lca(int u, int v)
// {
//     if (is_ancestor(u, v))
//         return u;
//     if (is_ancestor(v, u))
//         return v;
//     for (int i = l; i >= 0; --i) {
//         if (!is_ancestor(up[u][i], v))
//             u = up[u][i];
//     }
//     return up[u][0];
// }
// void preprocess(int root) {
//     tin.resize(N);
//     tout.resize(N);
//     timer = 0;
//     l = ceil(log2(N));
//     up.assign(N, vector<int>(l + 1));
//     dfs(root, root);
// }

// DSU
// resize leader,gsize -> make_set(i) for all i
// vector<int> leader;
// vector<int> gsize;
// vector<vector<int>> adj;
// int find_set(int v) {
//     if (v == leader[v])
//         return v;
//     return leader[v] = find_set(leader[v]);
// }
// void make_set(int v) {
//     leader[v] = v;
//     gsize[v] = 1;
// }
// void union_sets(int a, int b) {
//     a = find_set(a);
//     b = find_set(b);
//     if (a != b) {
//         if (gsize[a] < gsize[b])
//             swap(a, b);
//         leader[b] = a;
//         gsize[a] += gsize[b];
//     }
// }


signed main()
{
//#ifndef ONLINE_JUDGE
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
//#endif
fast_cin();


int n,s; cin>>n>>s;
vector<vector<char>> grid(n, vector<char>(n));
FOR(i,n){
    FOR(j,n){
        cin>>grid[i][j];
    }
}

pair<int,int> start;
pair<int,int> end;
FOR(i,n){
    FOR(j,n){
        if(grid[i][j] == 'M'){
            start.first = i;
            start.second = j;
        }
        if(grid[i][j] == 'D'){
            end.first = i;
            end.second = j;
        }
    }
}

// we have to do binary search for the time 

int l = -1;
int r = 800*800 + 5;

int dx[] = {-1, 0, 0, 1};
int dy[] = {0, -1, 1, 0};

while(l+1<r){
    int t = (l+r)/2;
    assert(t>=0);
    vector<vector<char>> temp = grid;
    // do flood fill till k

    queue<pair<int,int>> hive;
    FOR(i,n){
        FOR(j,n){
            if(temp[i][j] == 'H'){
                hive.push({i,j});
            }
        }
    }
    int d = t; // check 1
    while(!hive.empty() && d>0){
        int sz = hive.size();
        while(sz--){
            pair<int,int> top = hive.front();
            hive.pop();

            for(int k = 0; k<4; k++){
                int x = top.first + dx[k];
                int y = top.second + dy[k];
                if(x>=0 && y>=0 && x<n && y<n && (temp[x][y] == 'G' || temp[x][y] == 'M')){
                    temp[x][y] = 'H';
                    hive.push({x,y});
                }
            }
        }
        d--;
    }

    // start the race
    if(temp[start.first][start.second] == 'H'){
        r = t;
        // dbg(t);
        continue;
    }


    // cout<<t<<nl;
    queue<pair<int,int>> bear;
    bear.push(start);
    bool poss = false;
    while(!bear.empty()){
        // move it s steps
        int tmp = s;
        set<pair<int,int>> st;
        while(tmp>0){
            int sz = bear.size();
            while(sz>0){
                pair<int,int> top = bear.front();
                bear.pop();
                for(int k = 0; k<4; k++){
                    int x = top.first + dx[k];
                    int y = top.second + dy[k];
                    if(x>=0 && y>=0 && x<n && y<n && (temp[x][y] == 'G' || temp[x][y] == 'D')){
                        if(x == end.first && y == end.second){
                            poss = true;
                        }
                        temp[x][y] = 'M';
                        bear.push({x,y});
                    }
                }
                sz--;
            }
            tmp--;
        }

        while(!bear.empty()){
            st.insert(bear.front());
            bear.pop();
        }

        // now dekh lo jo consume ho rhe h
        int sz = hive.size();
        while(sz>0){
            pair<int,int> top = hive.front();
            hive.pop();

            for(int k = 0; k<4; k++){
                int x = top.first + dx[k];
                int y = top.second  + dy[k];
                if(x>=0 && y>=0 && x<n && y<n && (temp[x][y]=='G' || temp[x][y] == 'M')){
                    if(st.find({x,y}) != st.end()){
                        st.erase(st.find({x,y}));
                    }
                    temp[x][y] = 'H';
                    hive.push({x,y});
                }
            }
            sz--;
        }

        for(auto x: st){
            bear.push(x);
        }
        st.clear();
    }
    if(poss){
        l = t;
    }
    else{
        r = t;
    }
}

cout<<l<<nl;


return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	0 ms	212 KB	Output is correct
5	Correct	0 ms	212 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	227 ms	1856 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	1 ms	212 KB	Output is correct
10	Correct	1 ms	212 KB	Output is correct
11	Correct	1 ms	212 KB	Output is correct
12	Correct	1 ms	340 KB	Output is correct
13	Correct	1 ms	212 KB	Output is correct
14	Correct	2 ms	340 KB	Output is correct
15	Correct	1 ms	212 KB	Output is correct
16	Correct	1 ms	212 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	1 ms	212 KB	Output is correct
19	Correct	1 ms	212 KB	Output is correct
20	Correct	1 ms	212 KB	Output is correct
21	Correct	1 ms	212 KB	Output is correct
22	Correct	1 ms	212 KB	Output is correct
23	Correct	1 ms	212 KB	Output is correct
24	Correct	1 ms	212 KB	Output is correct
25	Correct	1 ms	212 KB	Output is correct
26	Correct	2 ms	212 KB	Output is correct
27	Correct	2 ms	340 KB	Output is correct
28	Correct	1 ms	212 KB	Output is correct
29	Correct	1 ms	212 KB	Output is correct
30	Correct	2 ms	212 KB	Output is correct
31	Correct	2 ms	340 KB	Output is correct
32	Correct	2 ms	340 KB	Output is correct
33	Correct	31 ms	592 KB	Output is correct
34	Correct	19 ms	468 KB	Output is correct
35	Correct	30 ms	596 KB	Output is correct
36	Correct	28 ms	664 KB	Output is correct
37	Correct	27 ms	668 KB	Output is correct
38	Correct	49 ms	596 KB	Output is correct
39	Correct	37 ms	736 KB	Output is correct
40	Correct	37 ms	736 KB	Output is correct
41	Correct	50 ms	760 KB	Output is correct
42	Correct	43 ms	820 KB	Output is correct
43	Correct	41 ms	724 KB	Output is correct
44	Correct	58 ms	852 KB	Output is correct
45	Correct	54 ms	852 KB	Output is correct
46	Correct	60 ms	928 KB	Output is correct
47	Correct	70 ms	852 KB	Output is correct
48	Correct	60 ms	1060 KB	Output is correct
49	Correct	58 ms	980 KB	Output is correct
50	Correct	84 ms	1072 KB	Output is correct
51	Correct	72 ms	1108 KB	Output is correct
52	Correct	67 ms	1108 KB	Output is correct
53	Correct	98 ms	1216 KB	Output is correct
54	Correct	79 ms	1208 KB	Output is correct
55	Correct	74 ms	1236 KB	Output is correct
56	Correct	113 ms	1236 KB	Output is correct
57	Correct	97 ms	1468 KB	Output is correct
58	Correct	87 ms	1468 KB	Output is correct
59	Correct	133 ms	1492 KB	Output is correct
60	Correct	126 ms	1620 KB	Output is correct
61	Correct	109 ms	1612 KB	Output is correct
62	Correct	148 ms	1740 KB	Output is correct
63	Correct	310 ms	1640 KB	Output is correct
64	Correct	217 ms	1740 KB	Output is correct
65	Correct	265 ms	1756 KB	Output is correct
66	Correct	297 ms	1764 KB	Output is correct
67	Correct	310 ms	1612 KB	Output is correct
68	Correct	233 ms	1684 KB	Output is correct
69	Correct	189 ms	1692 KB	Output is correct
70	Correct	201 ms	1696 KB	Output is correct
71	Correct	234 ms	1676 KB	Output is correct
72	Correct	227 ms	1620 KB	Output is correct
73	Correct	193 ms	2188 KB	Output is correct
74	Correct	264 ms	2220 KB	Output is correct
75	Correct	283 ms	2196 KB	Output is correct
76	Correct	266 ms	2180 KB	Output is correct
77	Correct	250 ms	2188 KB	Output is correct
78	Correct	253 ms	2136 KB	Output is correct
79	Correct	225 ms	2132 KB	Output is correct
80	Correct	242 ms	2140 KB	Output is correct
81	Correct	268 ms	2196 KB	Output is correct
82	Correct	238 ms	2132 KB	Output is correct
83	Correct	280 ms	2040 KB	Output is correct
84	Correct	225 ms	2048 KB	Output is correct
85	Correct	258 ms	2060 KB	Output is correct
86	Correct	273 ms	2128 KB	Output is correct
87	Correct	233 ms	2052 KB	Output is correct
88	Correct	302 ms	1956 KB	Output is correct
89	Correct	218 ms	1972 KB	Output is correct
90	Correct	223 ms	1896 KB	Output is correct
91	Correct	265 ms	1892 KB	Output is correct
92	Correct	258 ms	2076 KB	Output is correct