oj.uz

Submission #292974

# Submission time Handle Problem Language Result Execution time Memory
292974 2020-09-07T15:14:14 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
41 / 100
 5000 ms 60144 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];
    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:203:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  203 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sending.cpp:206:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  206 |         scanf("%d", &par[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sending.cpp:216:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  216 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
29.0 / 29.0

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

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 16 ms 25600 KB Output is correct
5 Correct 16 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 17 ms 25600 KB Output is correct
10 Correct 17 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 17 ms 25600 KB Output is correct
14 Correct 17 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 17 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 17 ms 25600 KB Output is correct
19 Correct 19 ms 25600 KB Output is correct
20 Correct 28 ms 26752 KB Output is correct
21 Correct 36 ms 26744 KB Output is correct
22 Correct 30 ms 26880 KB Output is correct
23 Correct 30 ms 26880 KB Output is correct
24 Correct 238 ms 26928 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 26880 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 29 ms 26880 KB Output is correct
30 Correct 42 ms 27000 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 42 ms 26880 KB Output is correct
33 Correct 63 ms 26880 KB Output is correct

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 16 ms 25600 KB Output is correct
5 Correct 16 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 17 ms 25600 KB Output is correct
10 Correct 17 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 17 ms 25600 KB Output is correct
14 Correct 17 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 17 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 17 ms 25600 KB Output is correct
19 Correct 19 ms 25600 KB Output is correct
20 Correct 28 ms 26752 KB Output is correct
21 Correct 36 ms 26744 KB Output is correct
22 Correct 30 ms 26880 KB Output is correct
23 Correct 30 ms 26880 KB Output is correct
24 Correct 238 ms 26928 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 26880 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 29 ms 26880 KB Output is correct
30 Correct 42 ms 27000 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 42 ms 26880 KB Output is correct
33 Correct 63 ms 26880 KB Output is correct
34 Correct 423 ms 48248 KB Output is correct
35 Incorrect 489 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 17 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 16 ms 25600 KB Output is correct
5 Correct 16 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 17 ms 25600 KB Output is correct
10 Correct 17 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 17 ms 25600 KB Output is correct
14 Correct 17 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 17 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 17 ms 25600 KB Output is correct
19 Correct 19 ms 25600 KB Output is correct
20 Correct 28 ms 26752 KB Output is correct
21 Correct 36 ms 26744 KB Output is correct
22 Correct 30 ms 26880 KB Output is correct
23 Correct 30 ms 26880 KB Output is correct
24 Correct 238 ms 26928 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 26880 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 29 ms 26880 KB Output is correct
30 Correct 42 ms 27000 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 42 ms 26880 KB Output is correct
33 Correct 63 ms 26880 KB Output is correct
34 Correct 423 ms 48248 KB Output is correct
35 Incorrect 489 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 449 ms 53464 KB Output is correct
2 Correct 1119 ms 59308 KB Output is correct
3 Incorrect 948 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 542 ms 52900 KB Output is correct
2 Correct 804 ms 52720 KB Output is correct
3 Correct 696 ms 60144 KB Output is correct
4 Correct 675 ms 59544 KB Output is correct
5 Execution timed out 5084 ms 53356 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #7
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 16 ms 25600 KB Output is correct
5 Correct 16 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 17 ms 25600 KB Output is correct
10 Correct 17 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 17 ms 25600 KB Output is correct
14 Correct 17 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 17 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 17 ms 25600 KB Output is correct
19 Correct 19 ms 25600 KB Output is correct
20 Correct 28 ms 26752 KB Output is correct
21 Correct 36 ms 26744 KB Output is correct
22 Correct 30 ms 26880 KB Output is correct
23 Correct 30 ms 26880 KB Output is correct
24 Correct 238 ms 26928 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 26880 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 29 ms 26880 KB Output is correct
30 Correct 42 ms 27000 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 42 ms 26880 KB Output is correct
33 Correct 63 ms 26880 KB Output is correct
34 Correct 423 ms 48248 KB Output is correct
35 Incorrect 489 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 17 ms 25600 KB Output is correct
2 Correct 17 ms 25600 KB Output is correct
3 Correct 17 ms 25600 KB Output is correct
4 Correct 16 ms 25600 KB Output is correct
5 Correct 16 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 17 ms 25600 KB Output is correct
8 Correct 17 ms 25600 KB Output is correct
9 Correct 17 ms 25600 KB Output is correct
10 Correct 17 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 17 ms 25600 KB Output is correct
14 Correct 17 ms 25600 KB Output is correct
15 Correct 17 ms 25600 KB Output is correct
16 Correct 17 ms 25600 KB Output is correct
17 Correct 18 ms 25600 KB Output is correct
18 Correct 17 ms 25600 KB Output is correct
19 Correct 19 ms 25600 KB Output is correct
20 Correct 28 ms 26752 KB Output is correct
21 Correct 36 ms 26744 KB Output is correct
22 Correct 30 ms 26880 KB Output is correct
23 Correct 30 ms 26880 KB Output is correct
24 Correct 238 ms 26928 KB Output is correct
25 Correct 20 ms 26880 KB Output is correct
26 Correct 29 ms 26880 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 27 ms 26624 KB Output is correct
29 Correct 29 ms 26880 KB Output is correct
30 Correct 42 ms 27000 KB Output is correct
31 Correct 34 ms 26880 KB Output is correct
32 Correct 42 ms 26880 KB Output is correct
33 Correct 63 ms 26880 KB Output is correct
34 Correct 423 ms 48248 KB Output is correct
35 Incorrect 489 ms 48248 KB Output isn't correct
36 Halted 0 ms 0 KB -