Submission #732175

#	Time	Username	Problem	Language	Result	Execution time	Memory
732175		PoonYaPat	Stations (IOI20_stations)	C++14	0 / 100	837 ms	920 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;

vector<int> adj[1001],A;
int ans[1001],cnt;

void dfs(int x, int par, int level) {
    if (level%2==0) ans[x]=++cnt;
    for (auto s : adj[x]) {
        if (s!=par) dfs(s,x,level+1);
    }
    if (level%2==1) ans[x]=++cnt;
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
    cnt=0;
    A.clear();
    for (int i=0; i<n; ++i) adj[i].clear();

    for (int i=0; i<n-1; ++i) {
        adj[u[i]].push_back(v[i]);
        adj[v[i]].push_back(u[i]);
    }
    dfs(0,0,0);
    for (int i=0; i<n; ++i) A.push_back(ans[i]);
    return A;
}

int find_next_station(int s, int t, vector<int> c) {
    if (s==1) {
        int ans;
        for (int i=c.size()-1; i>=0; --i) if (t<=c[i]) ans=i;
        return ans;
    }

    if (s>c[0]) {
        if (c.size()==1) return c[0];
        if (t<c[1] || t>s) return c[0];

        int ans;
        for (int i=1; i<c.size(); ++i) if (t>=c[i]) ans=i;
        return ans;

    } else {
        if (c.size()==1) return c[0];
        if (t<s || t>c[c.size()-2]) return c.back();

        int ans;
        for (int i=c.size()-2; i>=0; --i) if (t<=c[i]) ans=i;
        assert(ans!=0);
        return ans;
    }
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:42:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i=1; i<c.size(); ++i) if (t>=c[i]) ans=i;
      |                       ~^~~~~~~~~
stations.cpp:41:13: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   41 |         int ans;
      |             ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 0 / 10
• Subtask 5: 0 / 61