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Submission #292935

# Submission time Handle Problem Language Result Execution time Memory
292935 2020-09-07T14:52:52 Z 반딧불(#5810) ROI16_sending (ROI16_sending) C++17
41 / 100
 1188 ms 524288 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);
    }

    /// 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(x, y, i));
    }

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

Compilation message

sending.cpp: In function 'int main()':
sending.cpp:198:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  198 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sending.cpp:200:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  200 |         scanf("%d", &par[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sending.cpp:210:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  210 |         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 18 ms 25600 KB Output is correct
3 Correct 18 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25816 KB Output is correct
9 Correct 20 ms 25856 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25600 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 19 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 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 18 ms 25600 KB Output is correct
3 Correct 18 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25816 KB Output is correct
9 Correct 20 ms 25856 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25600 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 19 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 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 38 ms 27008 KB Output is correct
22 Correct 280 ms 73496 KB Output is correct
23 Correct 279 ms 75000 KB Output is correct
24 Correct 235 ms 26872 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 265 ms 73336 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 30 ms 26872 KB Output is correct
29 Correct 132 ms 77508 KB Output is correct
30 Correct 351 ms 97784 KB Output is correct
31 Correct 225 ms 72568 KB Output is correct
32 Correct 246 ms 68472 KB Output is correct
33 Correct 76 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 18 ms 25600 KB Output is correct
3 Correct 18 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25816 KB Output is correct
9 Correct 20 ms 25856 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25600 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 19 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 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 38 ms 27008 KB Output is correct
22 Correct 280 ms 73496 KB Output is correct
23 Correct 279 ms 75000 KB Output is correct
24 Correct 235 ms 26872 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 265 ms 73336 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 30 ms 26872 KB Output is correct
29 Correct 132 ms 77508 KB Output is correct
30 Correct 351 ms 97784 KB Output is correct
31 Correct 225 ms 72568 KB Output is correct
32 Correct 246 ms 68472 KB Output is correct
33 Correct 76 ms 31608 KB Output is correct
34 Correct 455 ms 48248 KB Output is correct
35 Incorrect 563 ms 48720 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 18 ms 25600 KB Output is correct
3 Correct 18 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25816 KB Output is correct
9 Correct 20 ms 25856 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25600 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 19 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 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 38 ms 27008 KB Output is correct
22 Correct 280 ms 73496 KB Output is correct
23 Correct 279 ms 75000 KB Output is correct
24 Correct 235 ms 26872 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 265 ms 73336 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 30 ms 26872 KB Output is correct
29 Correct 132 ms 77508 KB Output is correct
30 Correct 351 ms 97784 KB Output is correct
31 Correct 225 ms 72568 KB Output is correct
32 Correct 246 ms 68472 KB Output is correct
33 Correct 76 ms 31608 KB Output is correct
34 Correct 455 ms 48248 KB Output is correct
35 Incorrect 563 ms 48720 KB Output isn't correct
36 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 516 ms 57708 KB Output is correct
2 Correct 1188 ms 61864 KB Output is correct
3 Incorrect 1020 ms 61948 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 590 ms 53996 KB Output is correct
2 Correct 870 ms 55920 KB Output is correct
3 Runtime error 712 ms 524288 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 18 ms 25600 KB Output is correct
3 Correct 18 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25816 KB Output is correct
9 Correct 20 ms 25856 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25600 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 19 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 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 38 ms 27008 KB Output is correct
22 Correct 280 ms 73496 KB Output is correct
23 Correct 279 ms 75000 KB Output is correct
24 Correct 235 ms 26872 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 265 ms 73336 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 30 ms 26872 KB Output is correct
29 Correct 132 ms 77508 KB Output is correct
30 Correct 351 ms 97784 KB Output is correct
31 Correct 225 ms 72568 KB Output is correct
32 Correct 246 ms 68472 KB Output is correct
33 Correct 76 ms 31608 KB Output is correct
34 Correct 455 ms 48248 KB Output is correct
35 Incorrect 563 ms 48720 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 18 ms 25600 KB Output is correct
3 Correct 18 ms 25600 KB Output is correct
4 Correct 18 ms 25600 KB Output is correct
5 Correct 18 ms 25600 KB Output is correct
6 Correct 19 ms 25728 KB Output is correct
7 Correct 18 ms 25600 KB Output is correct
8 Correct 18 ms 25816 KB Output is correct
9 Correct 20 ms 25856 KB Output is correct
10 Correct 19 ms 25600 KB Output is correct
11 Correct 18 ms 25600 KB Output is correct
12 Correct 18 ms 25728 KB Output is correct
13 Correct 19 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 25728 KB Output is correct
19 Correct 18 ms 25600 KB Output is correct
20 Correct 31 ms 26752 KB Output is correct
21 Correct 38 ms 27008 KB Output is correct
22 Correct 280 ms 73496 KB Output is correct
23 Correct 279 ms 75000 KB Output is correct
24 Correct 235 ms 26872 KB Output is correct
25 Correct 21 ms 26880 KB Output is correct
26 Correct 265 ms 73336 KB Output is correct
27 Correct 23 ms 26624 KB Output is correct
28 Correct 30 ms 26872 KB Output is correct
29 Correct 132 ms 77508 KB Output is correct
30 Correct 351 ms 97784 KB Output is correct
31 Correct 225 ms 72568 KB Output is correct
32 Correct 246 ms 68472 KB Output is correct
33 Correct 76 ms 31608 KB Output is correct
34 Correct 455 ms 48248 KB Output is correct
35 Incorrect 563 ms 48720 KB Output isn't correct
36 Halted 0 ms 0 KB -