Submission #1222039

#	Time	Username	Problem	Language	Result	Execution time	Memory
1222039		SoMotThanhXuan	Dreaming (IOI13_dreaming)	C++20	100 / 100	88 ms	15688 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define FOR(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define REP(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)
#define mp make_pair
#define all(v) v.begin(), v.end()
#define uni(v) v.erase(unique(all(v)), v.end())
inline bool maximize(int &u, int v){
    return v > u ? u = v, true : false;
}
inline bool minimize(int &u, int v){
    return v < u ? u = v, true : false;
}
inline bool maximizell(long long &u, long long v){
    return v > u ? u = v, true : false;
}
inline bool minimizell(long long &u, long long v){
    return v < u ? u = v, true : false;
}
const int mod = 1e9 + 7;
inline int fastPow(int a, int n){
    if(n == 0) return 1;
    int t = fastPow(a, n >> 1);
    t = 1ll * t * t % mod;
    if(n & 1) t = 1ll * t * a % mod;
    return t;
}
inline void add(int &u, int v){
    u += v;
    if(u >= mod) u -= mod;
}
inline void sub(int &u, int v){
    u -= v;
    if(u < 0) u += mod;
}
const int maxN = 1e5 + 5;
const int inf = 2e9;
const long long infll = 1e18;
inline void degbug(){

}
int n, m, l;
vector<pair<int, int>> adj[maxN];
int cnt;
bool visited[maxN];
int mx1[maxN], out[maxN], mx2[maxN];
int root[maxN], sz[maxN];
int maxBranch[maxN];
int find_root(int v){
    return root[v] = root[v] == v ? v : find_root(root[v]);
}
bool union_set(int u, int v){
    u = find_root(u);
    v = find_root(v);
    if(u == v) return false;
    if(sz[u] < sz[v])swap(u, v);
    sz[u] += sz[v];
    root[v] = u;
    return true;
}
void dfs(int u){
    visited[u] = true;
//    cout << u << "\n";
    for(auto[v, w] : adj[u]){
        if(visited[v])continue;
        dfs(v);
        if(mx1[v] + w > mx1[u]){
            mx2[u] = mx1[u];
            mx1[u] = mx1[v] + w;
        }else maximize(mx2[u], mx1[v] + w);
    }
}
void dfs2(int u){
    visited[u] = true;
    for(auto[v, w] : adj[u]){
        if(visited[v])continue;
        out[v] = out[u] + w;
        if(mx1[v] + w == mx1[u])maximize(out[v], mx2[u] + w);
        else maximize(out[v], mx1[u] + w);
        dfs2(v);
    }
}
//int maxBranch[maxN];

void process(){
    cin >> n >> m >>  l;
    FOR(i, 0, n - 1)root[i] = i, sz[i] = 1;
    FOR(i, 1, m){
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].emplace_back(v, w);
        adj[v].emplace_back(u, w);
        union_set(u, v);
    }
    FOR(i, 0, n - 1){
        if(!visited[i]){
            dfs(i);
        }
    }
    FOR(i, 0, n - 1)visited[i] = false;
    FOR(i, 0, n - 1){
        if(!visited[i]){
            dfs2(i);
        }
    }
    int ans = 0;
    FOR(i, 0, n - 1){
        maximize(ans, max(mx1[i] + mx2[i], mx1[i] + out[i]));
    }
    vector<int> res;
    FOR(i, 0, n - 1)maxBranch[i] = inf;
    FOR(i, 0, n - 1)minimize(maxBranch[find_root(i)], max(mx1[i], out[i]));
    FOR(i, 0, n - 1)if(i == find_root(i))res.emplace_back(maxBranch[i]);
    sort(all(res));
    reverse(all(res));
    if(res.size() == 1){
        cout << ans;
    }else if(res.size() == 2){
        cout << max(ans, res[0] + res[1] + l);
    }else{
        ans = max(ans, res[0] + res[1] + l);
        ans = max(ans, res[1] + res[2] + 2 * l);
        cout << ans;
    }
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]){
    n = N;
    m = M;
    l = L;
    FOR(i, 0, n - 1)root[i] = i, sz[i] = 1;
    FOR(i, 0, m - 1){
        int u = A[i];
        int v = B[i];
        int w = T[i];
        adj[u].emplace_back(v, w);
        adj[v].emplace_back(u, w);
        union_set(u, v);
    }
    FOR(i, 0, n - 1){
        if(!visited[i]){
            dfs(i);
        }
    }
    FOR(i, 0, n - 1)visited[i] = false;
    FOR(i, 0, n - 1){
        if(!visited[i]){
            dfs2(i);
        }
    }
    int ans = 0;
    FOR(i, 0, n - 1){
        maximize(ans, max(mx1[i] + mx2[i], mx1[i] + out[i]));
    }
    vector<int> res;
    FOR(i, 0, n - 1)maxBranch[i] = inf;
    FOR(i, 0, n - 1)minimize(maxBranch[find_root(i)], max(mx1[i], out[i]));
    FOR(i, 0, n - 1)if(i == find_root(i))res.emplace_back(maxBranch[i]);
    sort(all(res));
    reverse(all(res));
    if(res.size() == 1){
        return ans;
    }else if(res.size() == 2){
        return max(ans, res[0] + res[1] + l);
    }else{
        ans = max(ans, res[0] + res[1] + l);
        ans = max(ans, res[1] + res[2] + 2 *  l);
        return ans;
    }
}
//#define LOVE "capgiatri"
//int main(){
//    if(fopen(LOVE".inp", "r")){
//        freopen(LOVE".inp", "r", stdin);
//        freopen(LOVE".out", "w", stdout);
//    }
//    ios_base::sync_with_stdio(false);
//    cin.tie(0);
//    cout.tie(0);
//
//    int t = 1;
////    cin >> t;
//    while(t--)
//        process();
////    cerr << '\n' << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s\n" ;
//    return 0;
//}

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 18 / 18
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23