oj.uz

Submission #293023

# Submission time Handle Problem Language Result Execution time Memory
293023 2020-09-07T15:37:14 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
53 / 100
 968 ms 63804 KB 
#include <bits/stdc++.h>
#define LIM 20

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];
    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){
            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 tmp = LCAdepth(inIdx[groupVec[i][j].first], inIdx[groupVec[i][j+1].first]);
            if(ans < tmp){
                ans = tmp, 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(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:200:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  200 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sending.cpp:203:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  203 |         scanf("%d", &par[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sending.cpp:213:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  213 |         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 17 ms 25600 KB Output is correct
3 Correct 19 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 17 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 20 ms 25668 KB Output is correct
9 Correct 19 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 19 ms 25600 KB Output is correct
12 Correct 16 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 20 ms 25728 KB Output is correct
15 Correct 21 ms 25600 KB Output is correct
16 Correct 16 ms 25600 KB Output is correct
17 Correct 32 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 16 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 19 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 17 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 20 ms 25668 KB Output is correct
9 Correct 19 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 19 ms 25600 KB Output is correct
12 Correct 16 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 20 ms 25728 KB Output is correct
15 Correct 21 ms 25600 KB Output is correct
16 Correct 16 ms 25600 KB Output is correct
17 Correct 32 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 34 ms 26684 KB Output is correct
21 Correct 30 ms 26752 KB Output is correct
22 Correct 34 ms 27008 KB Output is correct
23 Correct 36 ms 27000 KB Output is correct
24 Correct 31 ms 26880 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 27008 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 27 ms 26752 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 28 ms 26960 KB Output is correct
31 Correct 26 ms 27008 KB Output is correct
32 Correct 29 ms 27008 KB Output is correct
33 Correct 27 ms 27008 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 17 ms 25600 KB Output is correct
3 Correct 19 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 17 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 20 ms 25668 KB Output is correct
9 Correct 19 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 19 ms 25600 KB Output is correct
12 Correct 16 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 20 ms 25728 KB Output is correct
15 Correct 21 ms 25600 KB Output is correct
16 Correct 16 ms 25600 KB Output is correct
17 Correct 32 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 34 ms 26684 KB Output is correct
21 Correct 30 ms 26752 KB Output is correct
22 Correct 34 ms 27008 KB Output is correct
23 Correct 36 ms 27000 KB Output is correct
24 Correct 31 ms 26880 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 27008 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 27 ms 26752 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 28 ms 26960 KB Output is correct
31 Correct 26 ms 27008 KB Output is correct
32 Correct 29 ms 27008 KB Output is correct
33 Correct 27 ms 27008 KB Output is correct
34 Correct 444 ms 49160 KB Output is correct
35 Incorrect 511 ms 49144 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 17 ms 25600 KB Output is correct
3 Correct 19 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 17 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 20 ms 25668 KB Output is correct
9 Correct 19 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 19 ms 25600 KB Output is correct
12 Correct 16 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 20 ms 25728 KB Output is correct
15 Correct 21 ms 25600 KB Output is correct
16 Correct 16 ms 25600 KB Output is correct
17 Correct 32 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 34 ms 26684 KB Output is correct
21 Correct 30 ms 26752 KB Output is correct
22 Correct 34 ms 27008 KB Output is correct
23 Correct 36 ms 27000 KB Output is correct
24 Correct 31 ms 26880 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 27008 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 27 ms 26752 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 28 ms 26960 KB Output is correct
31 Correct 26 ms 27008 KB Output is correct
32 Correct 29 ms 27008 KB Output is correct
33 Correct 27 ms 27008 KB Output is correct
34 Correct 444 ms 49160 KB Output is correct
35 Incorrect 511 ms 49144 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 447 ms 54308 KB Output is correct
2 Correct 968 ms 60212 KB Output is correct
3 Incorrect 816 ms 60016 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 568 ms 53664 KB Output is correct
2 Correct 735 ms 53428 KB Output is correct
3 Correct 716 ms 63088 KB Output is correct
4 Correct 735 ms 62448 KB Output is correct
5 Correct 664 ms 58556 KB Output is correct
6 Correct 120 ms 54884 KB Output is correct
7 Correct 767 ms 63064 KB Output is correct
8 Correct 173 ms 51828 KB Output is correct
9 Correct 301 ms 50928 KB Output is correct
10 Correct 341 ms 63176 KB Output is correct
11 Correct 520 ms 63804 KB Output is correct
12 Correct 495 ms 63724 KB Output is correct
13 Correct 787 ms 63068 KB Output is correct

Subtask #7
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 19 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 17 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 20 ms 25668 KB Output is correct
9 Correct 19 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 19 ms 25600 KB Output is correct
12 Correct 16 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 20 ms 25728 KB Output is correct
15 Correct 21 ms 25600 KB Output is correct
16 Correct 16 ms 25600 KB Output is correct
17 Correct 32 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 34 ms 26684 KB Output is correct
21 Correct 30 ms 26752 KB Output is correct
22 Correct 34 ms 27008 KB Output is correct
23 Correct 36 ms 27000 KB Output is correct
24 Correct 31 ms 26880 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 27008 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 27 ms 26752 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 28 ms 26960 KB Output is correct
31 Correct 26 ms 27008 KB Output is correct
32 Correct 29 ms 27008 KB Output is correct
33 Correct 27 ms 27008 KB Output is correct
34 Correct 444 ms 49160 KB Output is correct
35 Incorrect 511 ms 49144 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 17 ms 25600 KB Output is correct
3 Correct 19 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 17 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 20 ms 25668 KB Output is correct
9 Correct 19 ms 25600 KB Output is correct
10 Correct 17 ms 25600 KB Output is correct
11 Correct 19 ms 25600 KB Output is correct
12 Correct 16 ms 25600 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 20 ms 25728 KB Output is correct
15 Correct 21 ms 25600 KB Output is correct
16 Correct 16 ms 25600 KB Output is correct
17 Correct 32 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 34 ms 26684 KB Output is correct
21 Correct 30 ms 26752 KB Output is correct
22 Correct 34 ms 27008 KB Output is correct
23 Correct 36 ms 27000 KB Output is correct
24 Correct 31 ms 26880 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 27008 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 27 ms 26752 KB Output is correct
29 Correct 28 ms 26880 KB Output is correct
30 Correct 28 ms 26960 KB Output is correct
31 Correct 26 ms 27008 KB Output is correct
32 Correct 29 ms 27008 KB Output is correct
33 Correct 27 ms 27008 KB Output is correct
34 Correct 444 ms 49160 KB Output is correct
35 Incorrect 511 ms 49144 KB Output isn't correct
36 Halted 0 ms 0 KB -