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Submission #292880

# Submission time Handle Problem Language Result Execution time Memory
292880 2020-09-07T14:34:07 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
41 / 100
 1202 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;
    oppVec[x].clear(), 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);
    }

    /// propagate to childs
    for(auto &chd: centroidChild[c]){
        findAnswer(chd, 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(min(x, y), max(x, y), i));
    }

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

Compilation message

sending.cpp: In function 'int main()':
sending.cpp:197:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  197 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sending.cpp:199:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  199 |         scanf("%d", &par[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sending.cpp:209:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  209 |         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 19 ms 25600 KB Output is correct
3 Correct 20 ms 25600 KB Output is correct
4 Correct 18 ms 25588 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 21 ms 25600 KB Output is correct
7 Correct 20 ms 25600 KB Output is correct
8 Correct 19 ms 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 18 ms 25708 KB Output is correct
11 Correct 20 ms 25600 KB Output is correct
12 Correct 19 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 19 ms 25728 KB Output is correct
17 Correct 19 ms 25728 KB Output is correct
18 Correct 20 ms 25728 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 18 ms 25600 KB Output is correct
2 Correct 19 ms 25600 KB Output is correct
3 Correct 20 ms 25600 KB Output is correct
4 Correct 18 ms 25588 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 21 ms 25600 KB Output is correct
7 Correct 20 ms 25600 KB Output is correct
8 Correct 19 ms 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 18 ms 25708 KB Output is correct
11 Correct 20 ms 25600 KB Output is correct
12 Correct 19 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 19 ms 25728 KB Output is correct
17 Correct 19 ms 25728 KB Output is correct
18 Correct 20 ms 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 30 ms 26880 KB Output is correct
21 Correct 38 ms 27120 KB Output is correct
22 Correct 274 ms 73336 KB Output is correct
23 Correct 269 ms 75000 KB Output is correct
24 Correct 243 ms 26872 KB Output is correct
25 Correct 21 ms 26876 KB Output is correct
26 Correct 284 ms 73464 KB Output is correct
27 Correct 24 ms 26752 KB Output is correct
28 Correct 29 ms 26880 KB Output is correct
29 Correct 139 ms 77432 KB Output is correct
30 Correct 336 ms 97528 KB Output is correct
31 Correct 241 ms 72648 KB Output is correct
32 Correct 249 ms 68472 KB Output is correct
33 Correct 83 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 19 ms 25600 KB Output is correct
3 Correct 20 ms 25600 KB Output is correct
4 Correct 18 ms 25588 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 21 ms 25600 KB Output is correct
7 Correct 20 ms 25600 KB Output is correct
8 Correct 19 ms 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 18 ms 25708 KB Output is correct
11 Correct 20 ms 25600 KB Output is correct
12 Correct 19 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 19 ms 25728 KB Output is correct
17 Correct 19 ms 25728 KB Output is correct
18 Correct 20 ms 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 30 ms 26880 KB Output is correct
21 Correct 38 ms 27120 KB Output is correct
22 Correct 274 ms 73336 KB Output is correct
23 Correct 269 ms 75000 KB Output is correct
24 Correct 243 ms 26872 KB Output is correct
25 Correct 21 ms 26876 KB Output is correct
26 Correct 284 ms 73464 KB Output is correct
27 Correct 24 ms 26752 KB Output is correct
28 Correct 29 ms 26880 KB Output is correct
29 Correct 139 ms 77432 KB Output is correct
30 Correct 336 ms 97528 KB Output is correct
31 Correct 241 ms 72648 KB Output is correct
32 Correct 249 ms 68472 KB Output is correct
33 Correct 83 ms 31608 KB Output is correct
34 Correct 459 ms 48376 KB Output is correct
35 Incorrect 567 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 19 ms 25600 KB Output is correct
3 Correct 20 ms 25600 KB Output is correct
4 Correct 18 ms 25588 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 21 ms 25600 KB Output is correct
7 Correct 20 ms 25600 KB Output is correct
8 Correct 19 ms 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 18 ms 25708 KB Output is correct
11 Correct 20 ms 25600 KB Output is correct
12 Correct 19 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 19 ms 25728 KB Output is correct
17 Correct 19 ms 25728 KB Output is correct
18 Correct 20 ms 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 30 ms 26880 KB Output is correct
21 Correct 38 ms 27120 KB Output is correct
22 Correct 274 ms 73336 KB Output is correct
23 Correct 269 ms 75000 KB Output is correct
24 Correct 243 ms 26872 KB Output is correct
25 Correct 21 ms 26876 KB Output is correct
26 Correct 284 ms 73464 KB Output is correct
27 Correct 24 ms 26752 KB Output is correct
28 Correct 29 ms 26880 KB Output is correct
29 Correct 139 ms 77432 KB Output is correct
30 Correct 336 ms 97528 KB Output is correct
31 Correct 241 ms 72648 KB Output is correct
32 Correct 249 ms 68472 KB Output is correct
33 Correct 83 ms 31608 KB Output is correct
34 Correct 459 ms 48376 KB Output is correct
35 Incorrect 567 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 506 ms 57840 KB Output is correct
2 Correct 1202 ms 63672 KB Output is correct
3 Incorrect 1030 ms 63412 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 565 ms 55024 KB Output is correct
2 Correct 854 ms 56940 KB Output is correct
3 Runtime error 693 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 19 ms 25600 KB Output is correct
3 Correct 20 ms 25600 KB Output is correct
4 Correct 18 ms 25588 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 21 ms 25600 KB Output is correct
7 Correct 20 ms 25600 KB Output is correct
8 Correct 19 ms 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 18 ms 25708 KB Output is correct
11 Correct 20 ms 25600 KB Output is correct
12 Correct 19 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 19 ms 25728 KB Output is correct
17 Correct 19 ms 25728 KB Output is correct
18 Correct 20 ms 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 30 ms 26880 KB Output is correct
21 Correct 38 ms 27120 KB Output is correct
22 Correct 274 ms 73336 KB Output is correct
23 Correct 269 ms 75000 KB Output is correct
24 Correct 243 ms 26872 KB Output is correct
25 Correct 21 ms 26876 KB Output is correct
26 Correct 284 ms 73464 KB Output is correct
27 Correct 24 ms 26752 KB Output is correct
28 Correct 29 ms 26880 KB Output is correct
29 Correct 139 ms 77432 KB Output is correct
30 Correct 336 ms 97528 KB Output is correct
31 Correct 241 ms 72648 KB Output is correct
32 Correct 249 ms 68472 KB Output is correct
33 Correct 83 ms 31608 KB Output is correct
34 Correct 459 ms 48376 KB Output is correct
35 Incorrect 567 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 19 ms 25600 KB Output is correct
3 Correct 20 ms 25600 KB Output is correct
4 Correct 18 ms 25588 KB Output is correct
5 Correct 17 ms 25600 KB Output is correct
6 Correct 21 ms 25600 KB Output is correct
7 Correct 20 ms 25600 KB Output is correct
8 Correct 19 ms 25728 KB Output is correct
9 Correct 19 ms 25728 KB Output is correct
10 Correct 18 ms 25708 KB Output is correct
11 Correct 20 ms 25600 KB Output is correct
12 Correct 19 ms 25728 KB Output is correct
13 Correct 18 ms 25600 KB Output is correct
14 Correct 19 ms 25600 KB Output is correct
15 Correct 19 ms 25984 KB Output is correct
16 Correct 19 ms 25728 KB Output is correct
17 Correct 19 ms 25728 KB Output is correct
18 Correct 20 ms 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 30 ms 26880 KB Output is correct
21 Correct 38 ms 27120 KB Output is correct
22 Correct 274 ms 73336 KB Output is correct
23 Correct 269 ms 75000 KB Output is correct
24 Correct 243 ms 26872 KB Output is correct
25 Correct 21 ms 26876 KB Output is correct
26 Correct 284 ms 73464 KB Output is correct
27 Correct 24 ms 26752 KB Output is correct
28 Correct 29 ms 26880 KB Output is correct
29 Correct 139 ms 77432 KB Output is correct
30 Correct 336 ms 97528 KB Output is correct
31 Correct 241 ms 72648 KB Output is correct
32 Correct 249 ms 68472 KB Output is correct
33 Correct 83 ms 31608 KB Output is correct
34 Correct 459 ms 48376 KB Output is correct
35 Incorrect 567 ms 48760 KB Output isn't correct
36 Halted 0 ms 0 KB -