Submission #1295211


Source Code Expand

#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

void stronglyConnectedComponents(const vector<vector<int> >& edges, vector<int>& indexConvert,
                                 vector<vector<int> >& nodesOut, vector<vector<int> >& edgesOut)
{
    const int n = edges.size();
    vector<int> num(n, -1), low(n, -1);
    vector<bool> isStk(n, false);
    stack<int> stk;
    int cnt = -1;
    nodesOut.clear();

    for(int i=0; i<n; ++i){
        stack<pair<int, unsigned> > arg;
        arg.push(make_pair(i, 0));

        while(!arg.empty()){
            int v = arg.top().first;
            unsigned j = arg.top().second;
            arg.pop();

            if(j == 0){
                if(num[v] != -1)
                    continue;
                num[v] = low[v] = ++ cnt;
                stk.push(v);
                isStk[v] = true;
            }
            else{
                int w = edges[v][j-1];
                if(isStk[w])
                    low[v] = min(low[v], low[w]);
            }

            if(j < edges[v].size()){
                arg.push(make_pair(v, j + 1));
                int w = edges[v][j];
                arg.push(make_pair(w, 0));
            }
            else if(low[v] == num[v]){
                nodesOut.push_back(vector<int>());
                for(;;){
                    int w = stk.top();
                    stk.pop();
                    isStk[w] = false;
                    nodesOut.back().push_back(w);
                    if(v == w)
                        break;
                }
            }
        }
    }

    reverse(nodesOut.begin(), nodesOut.end()); // DAGにするために反転させる
    const int m = nodesOut.size();
    indexConvert.resize(n);
    for(int i=0; i<m; ++i){
        for(unsigned j=0; j<nodesOut[i].size(); ++j)
            indexConvert[nodesOut[i][j]] = i;
    }
    edgesOut.assign(m, vector<int>());
    vector<set<int> > used(m);
    for(int i=0; i<n; ++i){
        for(unsigned j=0; j<edges[i].size(); ++j){
            int v = indexConvert[i];
            int w = indexConvert[edges[i][j]];
            if(v != w && used[v].find(w) == used[v].end()){
                edgesOut[v].push_back(w);
                used[v].insert(w);
            }
        }
    }
}

bool is2sat(int n, const vector<pair<int, bool> >& cs, vector<bool>& ans)
{
    vector<vector<int> > edges1(2*n);
    for(unsigned i=0; i<cs.size(); i+=2){
        int a = cs[i].first * 2 + (cs[i].second ? 0 : 1);
        int b = cs[i+1].first * 2 + (cs[i+1].second ? 0 : 1);
        edges1[a^1].push_back(b);
        edges1[b^1].push_back(a);
    }

    vector<int> indexConvert;
    vector<vector<int> > nodes, edges2;
    stronglyConnectedComponents(edges1, indexConvert, nodes, edges2);

    ans.resize(n);
    for(int i=0; i<n; ++i){
        if(indexConvert[2*i] < indexConvert[2*i+1])
            ans[i] = false;
        else if(indexConvert[2*i+1] < indexConvert[2*i])
            ans[i] = true;
        else
            return false;
    }
    return true;
}

class SegmentTree
{
private:
    int n;
    void getRangeIndex(int a, int b, int k, int l, int r, vector<int>& index){
        if(a <= l && r <= b){
            index.push_back(k);
        }
        else if(a <= r && l <= b){
            getRangeIndex(a, b, k*2+1, l, (l+r)/2, index);
            getRangeIndex(a, b, k*2+2, (l+r+1)/2, r, index);
        }
    }
public:
    SegmentTree(int n0){
        n = 1;
        while(n < n0)
            n *= 2;
    }
    int getNodeNum(){
        return 2 * n - 1;
    }
    int getLeafIndex(int a){
        return n - 1 + a;
    }
    int getParentIndex(int a){
        if(a == 0)
            return -1;
        else
            return (a - 1) / 2;
    }
    void getRangeIndex(int a, int b, vector<int>& index){
        index.clear();
        return getRangeIndex(a, b, 0, 0, n-1, index);
    }
};

int main()
{
    int n;
    cin >> n;
    vector<pair<int, int> > flag(2*n);
    for(int i=0; i<2*n; ++i){
        cin >> flag[i].first;
        flag[i].second = i;
    }

    sort(flag.begin(), flag.end());
    vector<int> index(2*n);
    for(int i=0; i<2*n; ++i)
        index[flag[i].second] = i;

    SegmentTree st(2*n);
    int m = st.getNodeNum();

    int left = 0;
    int right = 1000000000;
    while(left < right){
        vector<pair<int, bool> > cs;
        for(int a=1; a<m; ++a){
            int b = st.getParentIndex(a);
            cs.push_back(make_pair(a, false));
            cs.push_back(make_pair(b, true));
        }
        for(int i=0; i<n; ++i){
            cs.push_back(make_pair(st.getLeafIndex(index[2*i]), true));
            cs.push_back(make_pair(st.getLeafIndex(index[2*i+1]), true));
        }

        int mid = (left + right + 1) / 2;
        int j = 0;
        for(int i=0; i<2*n; ++i){
            while(flag[i].first - flag[j].first >= mid)
                ++ j;

            vector<int> v;
            st.getRangeIndex(j, i-1, v);
            for(int a : v){
                cs.push_back(make_pair(st.getLeafIndex(i), false));
                cs.push_back(make_pair(a, false));
            }
        }

        vector<bool> tmp;
        if(is2sat(m, cs, tmp))
            left = mid;
        else
            right = mid - 1;
    }

    cout << left << endl;

    return 0;
}

Submission Info

Submission Time
Task F - Flags
User mamekin
Language C++14 (GCC 5.4.1)
Score 1200
Code Size 5897 Byte
Status AC
Exec Time 3364 ms
Memory 50748 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 1200 / 1200
Status
AC × 3
AC × 30
Set Name Test Cases
Sample 00_example_01.txt, 00_example_02.txt, 00_example_03.txt
All 00_example_01.txt, 00_example_02.txt, 00_example_03.txt, 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, 23.txt, 24.txt, 25.txt, 26.txt, 27.txt
Case Name Status Exec Time Memory
00_example_01.txt AC 2 ms 256 KB
00_example_02.txt AC 2 ms 256 KB
00_example_03.txt AC 5 ms 256 KB
01.txt AC 77 ms 1528 KB
02.txt AC 39 ms 904 KB
03.txt AC 10 ms 460 KB
04.txt AC 19 ms 592 KB
05.txt AC 19 ms 576 KB
06.txt AC 2975 ms 38716 KB
07.txt AC 3017 ms 38692 KB
08.txt AC 2985 ms 38752 KB
09.txt AC 78 ms 1524 KB
10.txt AC 40 ms 900 KB
11.txt AC 10 ms 448 KB
12.txt AC 19 ms 596 KB
13.txt AC 19 ms 596 KB
14.txt AC 2989 ms 38944 KB
15.txt AC 2980 ms 38928 KB
16.txt AC 2974 ms 38860 KB
17.txt AC 78 ms 1656 KB
18.txt AC 38 ms 940 KB
19.txt AC 3091 ms 43524 KB
20.txt AC 3132 ms 43532 KB
21.txt AC 2787 ms 31080 KB
22.txt AC 2750 ms 31360 KB
23.txt AC 3194 ms 30812 KB
24.txt AC 2959 ms 32600 KB
25.txt AC 2987 ms 30620 KB
26.txt AC 3364 ms 50748 KB
27.txt AC 1 ms 256 KB