Submission #1022219

#	Time	Username	Problem	Language	Result	Execution time	Memory
1022219		hmm789	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	161 ms	28240 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
using namespace std;
 
vector<int> grp[1000], grp2[1000];
vector<vector<int>> p;
int cnt = 0, n;
int pos[1000], pos2[1000];
bool v[1000];

void dfs(int x) {
    grp[cnt].push_back(x);
    pos[x] = cnt;
    v[x] = 1;
    for(int i = 0; i < n; i++) if(!v[i] && p[x][i] == 1) dfs(i);
}

void dfs2(int x, int g) {
    v[x] = 1;
    grp2[g].push_back(x);
    pos2[x] = g;
    for(int i = 0; i < cnt; i++) if(!v[i] && p[grp[x][0]][grp[i][0]] == 2) dfs2(i, g);
}

int construct(std::vector<std::vector<int>> P) {
    n = (int)P.size();
    vector<vector<int>> ans;
    for(int i = 0; i < n; i++) {
        vector<int> v;
        for(int j = 0; j < n; j++) v.push_back(P[i][j]);
        p.push_back(v);
        vector<int> v2;
        v2.resize(n);
        ans.push_back(v2);
    }
    for(int i = 0; i < n; i++) if(!v[i]) {
        dfs(i); cnt++;
    }
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            if(pos[i] != pos[j] && p[i][j] == 1) return 0;
            if(pos[i] == pos[j] && p[i][j] != 1) return 0;
            if(p[grp[pos[i]][0]][grp[pos[j]][0]] != p[i][j]) return 0;
            if(p[i][j] == 3) return 0;
        }
    }
    memset(v, 0, sizeof(v));
    int c2 = 0;
    for(int i = 0; i < cnt; i++) if(!v[i]) dfs2(i, c2++);
    for(int i = 0; i < c2; i++) {
        for(int j : grp2[i]) {
            for(int k : grp2[i]) {
                if(p[grp[j][0]][grp[k][0]] == 0) return 0;
            }
        }
    }
    for(int i = 0; i < cnt; i++) {
        for(int j = 0; j < cnt; j++) {
            if(pos2[i] != pos2[j] && p[grp[i][0]][grp[j][0]] == 2) return 0;
        }
    }
    for(int i = 0; i < cnt; i++) {
        for(int j = 1; j < grp[i].size(); j++) {
            ans[grp[i][0]][grp[i][j]] = ans[grp[i][j]][grp[i][0]] = 1;
        }
    }
    memset(v, 0, sizeof(v));
    for(int i = 0; i < cnt; i++) if(!v[i]) {
        v[i] = 1;
        int prv = i, cnt2 = 0;
        for(int j = 0; j < cnt; j++) if(!v[j] && p[grp[i][0]][grp[j][0]] == 2) {
            ans[grp[prv][0]][grp[j][0]] = ans[grp[j][0]][grp[prv][0]] = 1;
            v[j] = 1;
            prv = j;
            cnt2++;
        }
        if(cnt2 == 1) return 0;
        if(i != prv) ans[grp[prv][0]][grp[i][0]] = ans[grp[i][0]][grp[prv][0]] = 1;
    }
    build(ans);
    return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:63:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |         for(int j = 1; j < grp[i].size(); j++) {
      |                        ~~^~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 21 / 21
• Subtask 6: 4 / 4