Submission #538729

#	Time	Username	Problem	Language	Result	Execution time	Memory
538729		dantoh000	Paths (RMI21_paths)	C++14	100 / 100	303 ms	23952 KiB

Main

#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
int n,k;
vector<ii> G[100005];
ll d[100005];
int p[100005][18];
int dep[100005];
int d1 = 0;
int d2 = 0;
int vis[19];
int dtp[100005];
int ondia[100005];
ll len[100005];
multiset<ll> top;
multiset<ll> bottom;
ll cursum = 0;
ll ans[100005];
void change(ll a, ll b){
    //printf("changing %lld for %lld\n",a,b);
    if (top.find(a) != top.end()) {
        top.erase(top.find(a));
        cursum -= a;
    }
    else if (bottom.find(a) != bottom.end()) bottom.erase(bottom.find(a));
    if (top.empty() || b >= *top.begin()){
        top.insert(b);
        cursum += b;
    }
    else{
        bottom.insert(b);
    }
    while (top.size() > k){
        auto it = top.begin();
        bottom.insert(*it);
        //printf("too many, removing %lld\n",*it);
        cursum -= *it;
        top.erase(it);
    }
    while (bottom.size() && top.size() < k){
        auto it = --bottom.end();
        top.insert(*it);
        //printf("too little, adding %lld\n",*it);
        cursum += *it;
        bottom.erase(it);
    }

}

void dfs(int u){
    for (auto v : G[u]){
        if (v.fi == p[u][0]) continue;
        d[v.fi] = d[u]+v.se;
        dep[v.fi] = dep[u]+1;
        p[v.fi][0] = u;
        dtp[v.fi] = v.se;
        dfs(v.fi);
    }
}

ll dfs2(int u){
    ll best = 0;
    for (auto v : G[u]){
        if (v.fi == p[u][0]) continue;
        ll x = dfs2(v.fi);
        if (best < x){
            if (best != 0) change(-1, best);
            best = x;
        }
        else{
            if (x != 0) change(-1, x);
        }
    }
    len[u] = best+dtp[u];
    //printf("len from %d = %lld\n",u,len[u]);
    return len[u];
}

void dfs3(int u, ll l){
    //printf("currently at %d: ans = %lld\n",u,cursum);
    //printf("at top: "); for (auto x : top) printf("%lld ",x); printf("\n");
    //printf("at bottom: "); for (auto x : bottom) printf("%lld ",x);  printf("\n");
    ans[u] = cursum;
    for (auto v : G[u]){
        if (v.fi == p[u][0]) continue;
        if (ondia[u] && !ondia[v.fi]){
            l = max(d[d2]-d[u], d[u]);
            change(l,l+v.se);
            change(len[v.fi], len[v.fi]-v.se);
            dfs3(v.fi, l+v.se);
            change(len[v.fi]-v.se,len[v.fi]);
            change(l+v.se,l);
        }
        else if (!ondia[u] && !ondia[v.fi]){
            change(l,l+v.se);
            change(len[v.fi], len[v.fi]-v.se);
            dfs3(v.fi, l+v.se);
            change(len[v.fi]-v.se,len[v.fi]);
            change(l+v.se,l);
        }
        else{
            change(d[d2]-d[u], d[d2]-d[v.fi]);
            change(d[u], d[v.fi]);
            dfs3(v.fi,l);
            change(d[v.fi],d[u]);
            change(d[d2]-d[v.fi],d[d2]-d[u]);
        }
    }
}
int lca(int a, int b){
    if (dep[a] > dep[b]) swap(a,b);
    int DD = dep[b] - dep[a];
    for (int k = 0; k < 18; k++){
        if (DD>>k&1){
            b = p[b][k];
        }
    }
    if (a == b) return a;
    for (int k = 17; k >= 0; k--){
        if (p[a][k] != -1 && p[a][k] != p[b][k]){
            a = p[a][k];
            b = p[b][k];
        }
    }
    assert(p[a][0] == p[b][0]);
    return p[a][0];
}
ll dist(int a, int b){
    return d[a] + d[b] - 2*d[lca(a,b)];
}
int main(){
    scanf("%d%d",&n,&k);
    for (int i = 1 ; i < n; i++){
        int a,b,c;
        scanf("%d%d%d",&a,&b,&c);
        G[a].push_back({b,c});
        G[b].push_back({a,c});
    }
    memset(p,-1,sizeof(p));
    dfs(1);
    for (int i = 1; i <= n; i++){
        if (d[i] > d[d1]) d1 = i;
    }
    memset(p,-1,sizeof(p));
    memset(d,0,sizeof(d));
    memset(dep,0,sizeof(dep));
    memset(dtp,0,sizeof(dtp));
    dfs(d1);
    for (int i = 1; i <= n; i++){
        if (d[i] > d[d2]) d2 = i;
    }
    for (int k = 1; k < 18; k++){
        for (int i = 1; i <= n; i++){
            if (p[i][k-1] != -1) p[i][k] = p[p[i][k-1]][k-1];
        }
    }
    //printf("diameter %d %d\n",d1,d2);
    int cur = d2;
    while (cur != -1){
        ondia[cur] = 1;
        cur = p[cur][0];
    }
    dfs2(d1);
    if (len[d1] != 0) change(-1, len[d1]);

    dfs3(d1, 0);
    for (int i = 1; i <= n; i++){
        printf("%lld\n",ans[i]);
    }








}

Compilation message (stderr)

Main.cpp: In function 'void change(ll, ll)':
Main.cpp:36:23: warning: comparison of integer expressions of different signedness: 'std::multiset<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   36 |     while (top.size() > k){
      |            ~~~~~~~~~~~^~~
Main.cpp:43:40: warning: comparison of integer expressions of different signedness: 'std::multiset<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   43 |     while (bottom.size() && top.size() < k){
      |                             ~~~~~~~~~~~^~~
Main.cpp: In function 'int main()':
Main.cpp:135:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |     scanf("%d%d",&n,&k);
      |     ~~~~~^~~~~~~~~~~~~~
Main.cpp:138:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  138 |         scanf("%d%d%d",&a,&b,&c);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 12 / 12
• Subtask 6: 32 / 32