oj.uz

Submission #292978

# Submission time Handle Problem Language Result Execution time Memory
292978 2020-09-07T15:16:44 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
41 / 100
 5000 ms 60200 KB 
#include <bits/stdc++.h>
#define LIM 19

using namespace std;

typedef long long ll;
typedef pair<int, int> pi;

struct Path{
    int x, y, idx;
    Path(){}
    Path(int x, int y, int idx): x(x), y(y), idx(idx){}

    bool operator<(const Path &r)const{
        if(x != r.x) return x < r.x;
        if(y != r.x) return y < r.y;
        return idx < r.idx;
    }
};

int n, k;
int par[200002];
vector<int> link[200002];
vector<int> centroidChild[200002];
int subTreeSize[200002];
bool centroidUsed[200002];
int centroidRoot;

int ans, ansX=1, ansY=2;

int getSubTreeSize(int x, int par){
    subTreeSize[x] = 1;
    for(auto &y: link[x]){
        if(y == par || centroidUsed[y]) continue;
        subTreeSize[x] += getSubTreeSize(y, x);
    }
    return subTreeSize[x];
}
int findCentroid(int x){
    int par = 0;
    int treeSize = getSubTreeSize(x, 0);
    while(1){
        int maxTreeSize = 0, maxTreeIdx = -1;
        for(auto &y: link[x]){
            if(centroidUsed[y] || y == par) continue;
            if(subTreeSize[y] > maxTreeSize) maxTreeSize = subTreeSize[y], maxTreeIdx = y;
        }
        if(maxTreeSize <= treeSize / 2){
            break;
        }
        par = x;
        x = maxTreeIdx;
    }
    centroidUsed[x] = 1;
    for(auto &y: link[x]){
        if(centroidUsed[y]) continue;
        int tmp = findCentroid(y);
        centroidChild[x].push_back(tmp);
    }
    return x;
}

int group[200002];
int in[200002], inCnt, depth[200002], inIdx[400002];
vector<pair<int, int> > oppVec[200002];
set<pair<int, int> > sets[200002];
int sparse[400002][LIM];
int cover[400002];

void dfsGroup(int x, int groupNum, int par = 0){
    group[x] = groupNum;
    in[x] = ++inCnt, inIdx[in[x]] = x;
    vector<pair<int, int> >().swap(oppVec[x]);
    sets[x].clear();
    for(auto &y: link[x]){
        if(centroidUsed[y] || y==par) continue;
        depth[y] = depth[x]+1;
        dfsGroup(y, groupNum, x);

        inIdx[++inCnt] = x;
    }
}

inline int LCAdepth(int x, int y){
    x = in[x], y = in[y];
    if(x>y) swap(x, y);
    int d = cover[y-x];
    if(x+(1<<d) < y-(1<<d)+1) exit(1);
    return min(sparse[x][d], sparse[y-(1<<d)+1][d]);
}

void put(int x, pair<int, int> p){
    auto it = sets[x].lower_bound(p);
    if(it != sets[x].end()){
        int tmp = depth[x] + LCAdepth(p.first, it->first);
        if(tmp > ans) ans = tmp, ansX = p.second, ansY = it->second;
    }
    if(it != sets[x].begin()){
        it = prev(it);
        int tmp = depth[x] + LCAdepth(p.first, it->first);
        if(tmp > ans) ans = tmp, ansX = p.second, ansY = it->second;
    }
    sets[x].insert(p);
}

void dfsCalc(int x, int par = 0){
    int minVal = INT_MAX, min_loc = -1;
    for(auto &y: link[x]){
        if(centroidUsed[y] || y==par) continue;
        dfsCalc(y, x);
        if(minVal > (int)sets[y].size()) minVal = sets[y].size(), min_loc = y;
    }

    sets[x].swap(sets[min_loc]);
    for(auto &y: link[x]){
        if(centroidUsed[y] || y==par || y==min_loc) continue;
        for(auto p: sets[y]) put(x, p);
        sets[y].clear();
    }
    for(auto p: oppVec[x]){
        put(x, p);
    }
}

void findAnswer(int c, vector<Path> &ust){
    vector<int> nearChild;
    vector<vector<pi> > groupVec;
    vector<vector<Path> > propVec;
    int s;

    for(auto &y: link[c]){
        if(centroidUsed[y]) continue;
        depth[y] = 1; nearChild.push_back(y);
    }
    if(nearChild.empty()) return;
    centroidUsed[c] = 1;
    s = (int)nearChild.size();
    groupVec.resize(s), propVec.resize(s);

    inCnt = depth[c] = 0;
    for(int i=0; i<s; i++){
        dfsGroup(nearChild[i], i);
        inIdx[++inCnt] = c;
    }
    for(int i=inCnt; i>=1; i--){
        sparse[i][0] = depth[inIdx[i]];
        for(int j=1; i+(1<<j)<=inCnt; j++){
            sparse[i][j] = min(sparse[i][j-1], sparse[i+(1<<(j-1))][j-1]);
        }
    }

    for(auto p: ust){
        if(p.x != c && p.y != c && group[p.x] == group[p.y]){
            propVec[group[p.x]].push_back(Path(p.x, p.y, p.idx));
            continue;
        }
        if(p.x != c) groupVec[group[p.x]].push_back({in[p.x], p.idx});
        if(p.y != c) groupVec[group[p.y]].push_back({in[p.y], p.idx});

        if(p.x != c && p.y != c){ /// insert into map
            int tmp1 = group[p.x], tmp2 = group[p.y];
            if(tmp1 > tmp2) swap(tmp1, tmp2);
            oppVec[p.x].push_back({p.y, p.idx});
            oppVec[p.y].push_back({p.x, p.idx});
        }
    }

    for(int i=0; i<s; i++){ /// check when common subtree is only one
        sort(groupVec[i].begin(), groupVec[i].end());
        for(int j=0; j<(int)groupVec[i].size()-1; j++){
            int tmpMin = INT_MAX;
            for(int x=groupVec[i][j].first; x<=groupVec[i][j+1].first; x++) tmpMin = min(tmpMin, depth[inIdx[x]]);
            if(ans < tmpMin){
                ans = tmpMin, ansX = groupVec[i][j].second, ansY = groupVec[i][j+1].second;
            }
        }

        for(int j=0; j<(int)groupVec[i].size(); j++){
            if(j && groupVec[i][j].first == groupVec[i][j-1].first) continue;
            int tmp1 = nearChild[i], tmp2 = inIdx[groupVec[i][j].first];
            if(tmp1 != tmp2) propVec[i].push_back(Path(min(tmp1, tmp2), max(tmp1, tmp2), groupVec[i][j].second));
        }
    }

    /// check when common subtree is two
    for(int i=0; i<s; i++){
        dfsCalc(nearChild[i], 0);
    }

    vector<int>().swap(nearChild);
    for(auto &x: groupVec) vector<pi>().swap(x);
    vector<vector<pi> >().swap(groupVec);

    /// propagate to childs
    for(auto &chd: centroidChild[c]){
        findAnswer(chd, propVec[group[chd]]);
        vector<Path>().swap(propVec[group[chd]]);
    }
}

int main(){
    for(int i=1; i<=400000; i++) cover[i] = cover[(i-1)/2]+1;

    scanf("%d %d", &n, &k);

    for(int i=2; i<=n; i++){
        scanf("%d", &par[i]);
        link[i].push_back(par[i]);
        link[par[i]].push_back(i);
    }
    centroidRoot = findCentroid(1);
    memset(centroidUsed, 0, sizeof(centroidUsed));

    vector<Path> st;
    for(int i=1; i<=k; i++){
        int x, y;
        scanf("%d %d", &x, &y);
        st.push_back(Path(x, y, i));
    }

    findAnswer(centroidRoot, st);
    printf("%d\n%d %d", ans, ansX, ansY);
}

Compilation message

sending.cpp: In function 'int main()':
sending.cpp:204:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  204 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sending.cpp:207:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  207 |         scanf("%d", &par[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sending.cpp:217:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  217 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 16 ms 25536 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 17 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 20 ms 25600 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 21 ms 25600 KB Output is correct
12 Correct 17 ms 25728 KB Output is correct
13 Correct 16 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 19 ms 25600 KB Output is correct
17 Correct 17 ms 25600 KB Output is correct
18 Correct 17 ms 25728 KB Output is correct
19 Correct 17 ms 25600 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 16 ms 25536 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 17 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 20 ms 25600 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 21 ms 25600 KB Output is correct
12 Correct 17 ms 25728 KB Output is correct
13 Correct 16 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 19 ms 25600 KB Output is correct
17 Correct 17 ms 25600 KB Output is correct
18 Correct 17 ms 25728 KB Output is correct
19 Correct 17 ms 25600 KB Output is correct
20 Correct 30 ms 26748 KB Output is correct
21 Correct 34 ms 26752 KB Output is correct
22 Correct 32 ms 26880 KB Output is correct
23 Correct 32 ms 26880 KB Output is correct
24 Correct 255 ms 26856 KB Output is correct
25 Correct 23 ms 27008 KB Output is correct
26 Correct 31 ms 26908 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 26 ms 26624 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 43 ms 26872 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 40 ms 26872 KB Output is correct
33 Correct 68 ms 26872 KB Output is correct

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 16 ms 25536 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 17 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 20 ms 25600 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 21 ms 25600 KB Output is correct
12 Correct 17 ms 25728 KB Output is correct
13 Correct 16 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 19 ms 25600 KB Output is correct
17 Correct 17 ms 25600 KB Output is correct
18 Correct 17 ms 25728 KB Output is correct
19 Correct 17 ms 25600 KB Output is correct
20 Correct 30 ms 26748 KB Output is correct
21 Correct 34 ms 26752 KB Output is correct
22 Correct 32 ms 26880 KB Output is correct
23 Correct 32 ms 26880 KB Output is correct
24 Correct 255 ms 26856 KB Output is correct
25 Correct 23 ms 27008 KB Output is correct
26 Correct 31 ms 26908 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 26 ms 26624 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 43 ms 26872 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 40 ms 26872 KB Output is correct
33 Correct 68 ms 26872 KB Output is correct
34 Correct 440 ms 48248 KB Output is correct
35 Incorrect 493 ms 48248 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #4
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 16 ms 25536 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 17 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 20 ms 25600 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 21 ms 25600 KB Output is correct
12 Correct 17 ms 25728 KB Output is correct
13 Correct 16 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 19 ms 25600 KB Output is correct
17 Correct 17 ms 25600 KB Output is correct
18 Correct 17 ms 25728 KB Output is correct
19 Correct 17 ms 25600 KB Output is correct
20 Correct 30 ms 26748 KB Output is correct
21 Correct 34 ms 26752 KB Output is correct
22 Correct 32 ms 26880 KB Output is correct
23 Correct 32 ms 26880 KB Output is correct
24 Correct 255 ms 26856 KB Output is correct
25 Correct 23 ms 27008 KB Output is correct
26 Correct 31 ms 26908 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 26 ms 26624 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 43 ms 26872 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 40 ms 26872 KB Output is correct
33 Correct 68 ms 26872 KB Output is correct
34 Correct 440 ms 48248 KB Output is correct
35 Incorrect 493 ms 48248 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 468 ms 53492 KB Output is correct
2 Correct 1139 ms 59372 KB Output is correct
3 Incorrect 954 ms 59120 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 536 ms 52972 KB Output is correct
2 Correct 783 ms 52720 KB Output is correct
3 Correct 693 ms 60200 KB Output is correct
4 Correct 673 ms 59540 KB Output is correct
5 Execution timed out 5063 ms 53360 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #7
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 16 ms 25536 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 17 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 20 ms 25600 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 21 ms 25600 KB Output is correct
12 Correct 17 ms 25728 KB Output is correct
13 Correct 16 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 19 ms 25600 KB Output is correct
17 Correct 17 ms 25600 KB Output is correct
18 Correct 17 ms 25728 KB Output is correct
19 Correct 17 ms 25600 KB Output is correct
20 Correct 30 ms 26748 KB Output is correct
21 Correct 34 ms 26752 KB Output is correct
22 Correct 32 ms 26880 KB Output is correct
23 Correct 32 ms 26880 KB Output is correct
24 Correct 255 ms 26856 KB Output is correct
25 Correct 23 ms 27008 KB Output is correct
26 Correct 31 ms 26908 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 26 ms 26624 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 43 ms 26872 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 40 ms 26872 KB Output is correct
33 Correct 68 ms 26872 KB Output is correct
34 Correct 440 ms 48248 KB Output is correct
35 Incorrect 493 ms 48248 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 16 ms 25536 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 17 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 20 ms 25600 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 21 ms 25600 KB Output is correct
12 Correct 17 ms 25728 KB Output is correct
13 Correct 16 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 19 ms 25600 KB Output is correct
17 Correct 17 ms 25600 KB Output is correct
18 Correct 17 ms 25728 KB Output is correct
19 Correct 17 ms 25600 KB Output is correct
20 Correct 30 ms 26748 KB Output is correct
21 Correct 34 ms 26752 KB Output is correct
22 Correct 32 ms 26880 KB Output is correct
23 Correct 32 ms 26880 KB Output is correct
24 Correct 255 ms 26856 KB Output is correct
25 Correct 23 ms 27008 KB Output is correct
26 Correct 31 ms 26908 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 26 ms 26624 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 43 ms 26872 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 40 ms 26872 KB Output is correct
33 Correct 68 ms 26872 KB Output is correct
34 Correct 440 ms 48248 KB Output is correct
35 Incorrect 493 ms 48248 KB Output isn't correct
36 Halted 0 ms 0 KB -