oj.uz

Submission #293008

# Submission time Handle Problem Language Result Execution time Memory
293008 2020-09-07T15:32:08 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
53 / 100
 919 ms 63852 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];
    assert(x && y);
    if(x>y) swap(x, y);
    int d = cover[y-x];
    return min(sparse[x][d], sparse[y-(1<<d)+1][d]);
}

inline 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 maxVal = -1, max_loc = -1;
    for(auto &y: link[x]){
        if(centroidUsed[y] || y==par) continue;
        dfsCalc(y, x);
        if(maxVal < (int)sets[y].size()) maxVal = sets[y].size(), max_loc = y;
    }

    sets[x].swap(sets[max_loc]);
    for(auto &y: link[x]){
        if(centroidUsed[y] || y==par || y==max_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]);
    }

    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 19 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 16 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 18 ms 25600 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 18 ms 25600 KB Output is correct
11 Correct 17 ms 25600 KB Output is correct
12 Correct 18 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 17 ms 25728 KB Output is correct
15 Correct 18 ms 25600 KB Output is correct
16 Correct 18 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 18 ms 25600 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 16 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 18 ms 25600 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 18 ms 25600 KB Output is correct
11 Correct 17 ms 25600 KB Output is correct
12 Correct 18 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 17 ms 25728 KB Output is correct
15 Correct 18 ms 25600 KB Output is correct
16 Correct 18 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 18 ms 25600 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 27 ms 26752 KB Output is correct
21 Correct 31 ms 26624 KB Output is correct
22 Correct 30 ms 27004 KB Output is correct
23 Correct 30 ms 27008 KB Output is correct
24 Correct 32 ms 26872 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 32 ms 27004 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 25 ms 26880 KB Output is correct
30 Correct 29 ms 27008 KB Output is correct
31 Correct 30 ms 27008 KB Output is correct
32 Correct 31 ms 27000 KB Output is correct
33 Correct 29 ms 27008 KB Output is correct

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 16 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 18 ms 25600 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 18 ms 25600 KB Output is correct
11 Correct 17 ms 25600 KB Output is correct
12 Correct 18 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 17 ms 25728 KB Output is correct
15 Correct 18 ms 25600 KB Output is correct
16 Correct 18 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 18 ms 25600 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 27 ms 26752 KB Output is correct
21 Correct 31 ms 26624 KB Output is correct
22 Correct 30 ms 27004 KB Output is correct
23 Correct 30 ms 27008 KB Output is correct
24 Correct 32 ms 26872 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 32 ms 27004 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 25 ms 26880 KB Output is correct
30 Correct 29 ms 27008 KB Output is correct
31 Correct 30 ms 27008 KB Output is correct
32 Correct 31 ms 27000 KB Output is correct
33 Correct 29 ms 27008 KB Output is correct
34 Correct 416 ms 48376 KB Output is correct
35 Incorrect 475 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 19 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 16 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 18 ms 25600 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 18 ms 25600 KB Output is correct
11 Correct 17 ms 25600 KB Output is correct
12 Correct 18 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 17 ms 25728 KB Output is correct
15 Correct 18 ms 25600 KB Output is correct
16 Correct 18 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 18 ms 25600 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 27 ms 26752 KB Output is correct
21 Correct 31 ms 26624 KB Output is correct
22 Correct 30 ms 27004 KB Output is correct
23 Correct 30 ms 27008 KB Output is correct
24 Correct 32 ms 26872 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 32 ms 27004 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 25 ms 26880 KB Output is correct
30 Correct 29 ms 27008 KB Output is correct
31 Correct 30 ms 27008 KB Output is correct
32 Correct 31 ms 27000 KB Output is correct
33 Correct 29 ms 27008 KB Output is correct
34 Correct 416 ms 48376 KB Output is correct
35 Incorrect 475 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 436 ms 53484 KB Output is correct
2 Correct 919 ms 59452 KB Output is correct
3 Incorrect 831 ms 59116 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 548 ms 52976 KB Output is correct
2 Correct 705 ms 52560 KB Output is correct
3 Correct 720 ms 63084 KB Output is correct
4 Correct 698 ms 62576 KB Output is correct
5 Correct 646 ms 57968 KB Output is correct
6 Correct 94 ms 54124 KB Output is correct
7 Correct 716 ms 62960 KB Output is correct
8 Correct 150 ms 51056 KB Output is correct
9 Correct 296 ms 50288 KB Output is correct
10 Correct 323 ms 63340 KB Output is correct
11 Correct 501 ms 63852 KB Output is correct
12 Correct 477 ms 63852 KB Output is correct
13 Correct 761 ms 63260 KB Output is correct

Subtask #7
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 16 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 18 ms 25600 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 18 ms 25600 KB Output is correct
11 Correct 17 ms 25600 KB Output is correct
12 Correct 18 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 17 ms 25728 KB Output is correct
15 Correct 18 ms 25600 KB Output is correct
16 Correct 18 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 18 ms 25600 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 27 ms 26752 KB Output is correct
21 Correct 31 ms 26624 KB Output is correct
22 Correct 30 ms 27004 KB Output is correct
23 Correct 30 ms 27008 KB Output is correct
24 Correct 32 ms 26872 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 32 ms 27004 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 25 ms 26880 KB Output is correct
30 Correct 29 ms 27008 KB Output is correct
31 Correct 30 ms 27008 KB Output is correct
32 Correct 31 ms 27000 KB Output is correct
33 Correct 29 ms 27008 KB Output is correct
34 Correct 416 ms 48376 KB Output is correct
35 Incorrect 475 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 19 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 16 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 18 ms 25600 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25600 KB Output is correct
9 Correct 18 ms 25600 KB Output is correct
10 Correct 18 ms 25600 KB Output is correct
11 Correct 17 ms 25600 KB Output is correct
12 Correct 18 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 17 ms 25728 KB Output is correct
15 Correct 18 ms 25600 KB Output is correct
16 Correct 18 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 18 ms 25600 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 27 ms 26752 KB Output is correct
21 Correct 31 ms 26624 KB Output is correct
22 Correct 30 ms 27004 KB Output is correct
23 Correct 30 ms 27008 KB Output is correct
24 Correct 32 ms 26872 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 32 ms 27004 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 25 ms 26880 KB Output is correct
30 Correct 29 ms 27008 KB Output is correct
31 Correct 30 ms 27008 KB Output is correct
32 Correct 31 ms 27000 KB Output is correct
33 Correct 29 ms 27008 KB Output is correct
34 Correct 416 ms 48376 KB Output is correct
35 Incorrect 475 ms 48248 KB Output isn't correct
36 Halted 0 ms 0 KB -