oj.uz

Submission #292962

# Submission time Handle Problem Language Result Execution time Memory
292962 2020-09-07T15:03:44 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
41 / 100
 1192 ms 524292 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] = 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:205:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  205 |         scanf("%d", &par[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sending.cpp:215:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  215 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 25600 KB Output is correct
2 Correct 20 ms 25600 KB Output is correct
3 Correct 18 ms 25632 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 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 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25728 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 18 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 18 ms 25728 KB Output is correct
17 Correct 18 ms 25728 KB Output is correct
18 Correct 19 ms 25704 KB Output is correct
19 Correct 18 ms 25728 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 25600 KB Output is correct
2 Correct 20 ms 25600 KB Output is correct
3 Correct 18 ms 25632 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 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 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25728 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 18 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 18 ms 25728 KB Output is correct
17 Correct 18 ms 25728 KB Output is correct
18 Correct 19 ms 25704 KB Output is correct
19 Correct 18 ms 25728 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 39 ms 27008 KB Output is correct
22 Correct 267 ms 73440 KB Output is correct
23 Correct 272 ms 74872 KB Output is correct
24 Correct 227 ms 26812 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 264 ms 73336 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 28 ms 26880 KB Output is correct
29 Correct 130 ms 77432 KB Output is correct
30 Correct 346 ms 97596 KB Output is correct
31 Correct 241 ms 72696 KB Output is correct
32 Correct 251 ms 68600 KB Output is correct
33 Correct 74 ms 31608 KB Output is correct

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 25600 KB Output is correct
2 Correct 20 ms 25600 KB Output is correct
3 Correct 18 ms 25632 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 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 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25728 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 18 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 18 ms 25728 KB Output is correct
17 Correct 18 ms 25728 KB Output is correct
18 Correct 19 ms 25704 KB Output is correct
19 Correct 18 ms 25728 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 39 ms 27008 KB Output is correct
22 Correct 267 ms 73440 KB Output is correct
23 Correct 272 ms 74872 KB Output is correct
24 Correct 227 ms 26812 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 264 ms 73336 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 28 ms 26880 KB Output is correct
29 Correct 130 ms 77432 KB Output is correct
30 Correct 346 ms 97596 KB Output is correct
31 Correct 241 ms 72696 KB Output is correct
32 Correct 251 ms 68600 KB Output is correct
33 Correct 74 ms 31608 KB Output is correct
34 Correct 450 ms 48376 KB Output is correct
35 Incorrect 518 ms 48760 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #4
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 25600 KB Output is correct
2 Correct 20 ms 25600 KB Output is correct
3 Correct 18 ms 25632 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 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 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25728 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 18 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 18 ms 25728 KB Output is correct
17 Correct 18 ms 25728 KB Output is correct
18 Correct 19 ms 25704 KB Output is correct
19 Correct 18 ms 25728 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 39 ms 27008 KB Output is correct
22 Correct 267 ms 73440 KB Output is correct
23 Correct 272 ms 74872 KB Output is correct
24 Correct 227 ms 26812 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 264 ms 73336 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 28 ms 26880 KB Output is correct
29 Correct 130 ms 77432 KB Output is correct
30 Correct 346 ms 97596 KB Output is correct
31 Correct 241 ms 72696 KB Output is correct
32 Correct 251 ms 68600 KB Output is correct
33 Correct 74 ms 31608 KB Output is correct
34 Correct 450 ms 48376 KB Output is correct
35 Incorrect 518 ms 48760 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 524 ms 57432 KB Output is correct
2 Correct 1192 ms 60304 KB Output is correct
3 Incorrect 1043 ms 60296 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 594 ms 53188 KB Output is correct
2 Correct 878 ms 55200 KB Output is correct
3 Runtime error 695 ms 524292 KB Execution killed with signal 9
4 Halted 0 ms 0 KB -

Subtask #7
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 25600 KB Output is correct
2 Correct 20 ms 25600 KB Output is correct
3 Correct 18 ms 25632 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 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 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25728 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 18 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 18 ms 25728 KB Output is correct
17 Correct 18 ms 25728 KB Output is correct
18 Correct 19 ms 25704 KB Output is correct
19 Correct 18 ms 25728 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 39 ms 27008 KB Output is correct
22 Correct 267 ms 73440 KB Output is correct
23 Correct 272 ms 74872 KB Output is correct
24 Correct 227 ms 26812 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 264 ms 73336 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 28 ms 26880 KB Output is correct
29 Correct 130 ms 77432 KB Output is correct
30 Correct 346 ms 97596 KB Output is correct
31 Correct 241 ms 72696 KB Output is correct
32 Correct 251 ms 68600 KB Output is correct
33 Correct 74 ms 31608 KB Output is correct
34 Correct 450 ms 48376 KB Output is correct
35 Incorrect 518 ms 48760 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 25600 KB Output is correct
2 Correct 20 ms 25600 KB Output is correct
3 Correct 18 ms 25632 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 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 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25728 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 18 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 18 ms 25728 KB Output is correct
17 Correct 18 ms 25728 KB Output is correct
18 Correct 19 ms 25704 KB Output is correct
19 Correct 18 ms 25728 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 39 ms 27008 KB Output is correct
22 Correct 267 ms 73440 KB Output is correct
23 Correct 272 ms 74872 KB Output is correct
24 Correct 227 ms 26812 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 264 ms 73336 KB Output is correct
27 Correct 22 ms 26624 KB Output is correct
28 Correct 28 ms 26880 KB Output is correct
29 Correct 130 ms 77432 KB Output is correct
30 Correct 346 ms 97596 KB Output is correct
31 Correct 241 ms 72696 KB Output is correct
32 Correct 251 ms 68600 KB Output is correct
33 Correct 74 ms 31608 KB Output is correct
34 Correct 450 ms 48376 KB Output is correct
35 Incorrect 518 ms 48760 KB Output isn't correct
36 Halted 0 ms 0 KB -