Submission #132351

#	Time	Username	Problem	Language	Result	Execution time	Memory
132351		duality	Construction of Highway (JOI18_construction)	C++11	100 / 100	722 ms	23032 KiB

construction

#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
typedef long long int LLI;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pii> vpii;

int C[100000];
vi adjList[100000];
int parent[100000][17],order[100000];
int depth[100000];
int disc[100000],fin[100000],inv[100000],num = 0;
int doDFS(int u,int d) {
    int i;
    depth[u] = d,disc[u] = num++,inv[num-1] = u;
    for (i = 0; i < adjList[u].size(); i++) doDFS(adjList[u][i],d+1);
    fin[u] = num;
    return 0;
}
int good[100000],pref[100000];
vpii chains;
vi sorted;
int bit[100001],bit2[100001];
int update(int u,int N) {
    int i;
    for (i = disc[u]+1; i <= N; i += i & (-i)) bit[i] += good[u] ? -1:1;
    for (i = fin[u]+1; i <= N; i += i & (-i)) bit[i] += good[u] ? 1:-1;
    good[u] ^= 1;
    return 0;
}
int query(int u) {
    int i,sum = 0;
    for (i = disc[u]+1; i > 0; i -= i & (-i)) sum += bit[i];
    return sum;
}
int main() {
    int i;
    int N,A,B;
    scanf("%d",&N);
    for (i = 0; i < N; i++) scanf("%d",&C[i]);
    parent[0][0] = -1;
    for (i = 0; i < N-1; i++) {
        scanf("%d %d",&A,&B);
        A--,B--;
        adjList[A].pb(B),parent[B][0] = A;
        order[i] = B;
    }
    doDFS(0,0);

    int j,k;
    for (i = 1; (1 << i) < N; i++) {
        for (j = 0; j < N; j++) {
            if (parent[j][i-1] != -1) parent[j][i] = parent[parent[j][i-1]][i-1];
            else parent[j][i] = -1;
        }
    }
    int logn = i;
    for (i = 0; i < N; i++) pref[i] = -1;
    for (i = 0; i < N-1; i++) {
        int u = order[i];
        while (u != 0) {
            int v = pref[parent[u][0]];
            if (v != -1) update(v,N);
            pref[parent[u][0]] = u,update(u,N);
            int w = parent[u][0];
            for (j = logn-1; j >= 0; j--) {
                if ((parent[w][j] != -1) && (query(w) == (query(parent[w][j])+(1 << j)))) w = parent[w][j];
            }
            if (v != -1) C[v] = C[w];
            chains.pb(mp(C[w],depth[u]-depth[w])),sorted.pb(C[w]);
            u = w;
        }
        LLI ans = 0;
        sort(sorted.begin(),sorted.end());
        sorted.resize(unique(sorted.begin(),sorted.end())-sorted.begin());
        for (j = 0; j < chains.size(); j++) {
            int p = lower_bound(sorted.begin(),sorted.end(),chains[j].first)-sorted.begin();
            for (k = p; k > 0; k -= k & (-k)) ans += (LLI) chains[j].second*bit2[k];
            for (k = p+1; k <= sorted.size(); k += k & (-k)) bit2[k] += chains[j].second;
        }
        printf("%lld\n",ans);
        C[0] = C[order[i]];
        for (j = 0; j <= sorted.size(); j++) bit2[j] = 0;
        chains.clear(),sorted.clear();
    }

    return 0;
}

Compilation message (stderr)

construction.cpp: In function 'int doDFS(int, int)':
construction.cpp:18:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i = 0; i < adjList[u].size(); i++) doDFS(adjList[u][i],d+1);
                 ~~^~~~~~~~~~~~~~~~~~~
construction.cpp: In function 'int main()':
construction.cpp:78:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (j = 0; j < chains.size(); j++) {
                     ~~^~~~~~~~~~~~~~~
construction.cpp:81:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (k = p+1; k <= sorted.size(); k += k & (-k)) bit2[k] += chains[j].second;
                           ~~^~~~~~~~~~~~~~~~
construction.cpp:85:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (j = 0; j <= sorted.size(); j++) bit2[j] = 0;
                     ~~^~~~~~~~~~~~~~~~
construction.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&N);
     ~~~~~^~~~~~~~~
construction.cpp:42:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (i = 0; i < N; i++) scanf("%d",&C[i]);
                             ~~~~~^~~~~~~~~~~~
construction.cpp:45:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d",&A,&B);
         ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 84 / 84