Submission #80151

#	Time	Username	Problem	Language	Result	Execution time	Memory
80151		Sherazin	Teleporters (IOI08_teleporters)	C++14	85 / 100	1097 ms	66560 KiB

teleporters

#include <bits/stdc++.h>

#define pii pair<int, int>
#define x first
#define y second

using namespace std;

const int N = 2e6+5;

int n, m;
int chk[N], sz[N], mp[N], comp;
vector<int> pos;

int get(int x) { return lower_bound(pos.begin(), pos.end(), x) - pos.begin(); }

int main() {
       scanf("%d %d", &n, &m);
       for(int i = 1, a, b; i <= n; i++) {
              scanf("%d %d", &a, &b);
              pos.emplace_back(a), pos.emplace_back(b);
              mp[a] = b, mp[b] = a;
       }
       pos.emplace_back(N-1);
       sort(pos.begin(), pos.end());
       for(int i = 0; i < 2*n; i++) if(!chk[i]) {
              chk[i] = ++comp;
              queue<int> Q;
              Q.emplace(i);
              while(!Q.empty()) {
                    int u = Q.front();
                    Q.pop();
                    ++sz[comp];
                    int v = get(mp[pos[u]]) + 1;
                    if(chk[v] || v == 2*n) continue;
                    chk[v] = comp;
                    Q.emplace(v);
              }
       }
       int ans = sz[1];
       vector<int> V;
       for(int i = 2; i <= comp; i++) V.emplace_back(sz[i]);
       sort(V.begin(), V.end(), greater<int>());
       for(int i = 0; i < V.size() && m; i++, m--) ans += V[i] + 2;
       if(m) ans += 2*(m - (m & 1)) + (m & 1);
       printf("%d\n", ans);

       return 0;
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:44:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
        for(int i = 0; i < V.size() && m; i++, m--) ans += V[i] + 2;
                       ~~^~~~~~~~~~
teleporters.cpp:18:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
        scanf("%d %d", &n, &m);
        ~~~~~^~~~~~~~~~~~~~~~~
teleporters.cpp:20:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
               scanf("%d %d", &a, &b);
               ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
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