Submission #98179

#	Time	Username	Problem	Language	Result	Execution time	Memory
98179		dalgerok	Pictionary (COCI18_pictionary)	C++17	140 / 140	469 ms	25644 KiB

pictionary

#include<bits/stdc++.h>
using namespace std;



const int N = 1e5 + 5, M = 20;




int n, m, k, pp[N], d[N];
int p[M + 1][N], dp[M + 1][N];
vector < pair < int, int > > g[N];

int dsu_get(int v){
    return pp[v] == v ? v : pp[v] = dsu_get(pp[v]);
}

void dfs(int v, int pr = 0, int prval = 0){
    p[0][v] = pr;
    dp[0][v] = prval;
    for(int i = 1; i <= M; i++){
        p[i][v] = p[i - 1][p[i - 1][v]];
        dp[i][v] = max(dp[i - 1][v], dp[i - 1][p[i - 1][v]]);
    }
    for(auto it : g[v]){
        int to = it.first, len = it.second;
        if(to != pr){
            d[to] = d[v] + 1;
            dfs(to, v, len);
        }
    }
}
inline int lca(int x, int y){
    if(x == y){
        return x;
    }
    if(d[x] > d[y]){
        swap(x, y);
    }
    int len = d[y] - d[x];
    for(int i = 0; i <= M; i++){
        if((len >> i) & 1){
            y = p[i][y];
        }
    }
    if(x == y){
        return x;
    }
    for(int i = M; i >= 0; i--){
        if(p[i][x] != p[i][y]){
            x = p[i][x];
            y = p[i][y];
        }
    }
    return p[0][x];
}

inline int get(int x, int y){
    if(x == y){
        return 0;
    }
    int ans = 0, len = d[y] - d[x];
    for(int i = M; i >= 0; i--){
        if((len >> i) & 1){
            ans = max(ans, dp[i][y]);
            y = p[i][y];
        }
    }
    return ans;
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n >> m >> k;
    for(int i = 1; i <= n; i++){
        pp[i] = i;
    }
    for(int i = m; i >= 1; i--){
        for(int j = 2; j * i <= n; j++){
            if(dsu_get(i) != dsu_get(i * j)){
                pp[dsu_get(i)] = dsu_get(i * j);
                g[i].push_back(make_pair(i * j, m - i + 1));
                g[i * j].push_back(make_pair(i, m - i + 1));
            }
        }
    }
    dfs(1);
    while(k--){
        int x, y;
        cin >> x >> y;
        int z = lca(x, y);
        cout << max(get(z, x), get(z, y)) << "\n";
    }
}

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 14 / 14
• Subtask 6: 14 / 14
• Subtask 7: 14 / 14
• Subtask 8: 14 / 14
• Subtask 9: 14 / 14
• Subtask 10: 14 / 14