Submission #530453

#	Time	Username	Problem	Language	Result	Execution time	Memory
530453		__Variatto	Dreaming (IOI13_dreaming)	C++17	0 / 100	47 ms	14220 KiB

dreaming

#include <bits/stdc++.h>
#include"dreaming.h"
using namespace std;
#define pb push_back
#define fi first
#define se second
#define ll long long
const int MAX=1e5+10, MAXV=1e9+10;
int n, m, l, odl[MAX][2];
vector<pair<int,int>>g[MAX];
pair<int,int>maxi;
bool odw[MAX];
void dfso(int v, int oj, int x, int nr){
    odl[v][nr]=x;
    odw[v]=true;
    maxi=max(maxi, {x, v});
    for(auto s: g[v])
        if(s.fi!=oj)
            dfso(s.fi, v, x+s.se, nr);
}
pair<int,int>mini;
void dfs(int v, int oj){
    mini=min(mini, {max(odl[v][0], odl[v][1]), v});
    for(auto s: g[v])
        if(s.fi!=oj)
            dfs(s.fi,v);
}
int travelTime(int N, int M, int L, int a[], int b[], int t[]){
    n=N, m=M, l=L;
    for(int i=0; i<m; i++)
        g[a[i]].pb({b[i], t[i]}), g[b[i]].pb({a[i], t[i]});
    int ls1=-1, ls2=-1, lmid=-1, dl=0, lmids1=0, lmids2=0;
    for(int i=0; i<n; i++){
        if(odw[i])
            continue;
        maxi={0,0};
        dfso(i, i, 0, 0);
        int s1=maxi.se;
        maxi={0,0};
        dfso(s1, s1, 0, 0);
        int s2=maxi.se;
        maxi={0,0};
        dfso(s2, s2, 0, 1);
        mini={MAXV,0};
        dfs(i, i);
        int mid=mini.se;
        int mids1=odl[mid][0], mids2=odl[mid][1];
        if(ls1==-1){
            ls1=s1, ls2=s2, lmid=mid, dl=odl[s2][0], lmids1=mids1, lmids2=mids2;
            continue;
        }
        if(dl<max(mids1, mids2)+max(lmids1, lmids2)+l){
            dl=max(mids1, mids2)+max(lmids1, lmids2)+l;
            int nmid, ns1, ns2, nmids1, nmids2;
            if(mids1>mids2 && lmids1>lmids2){
                ns1=s1, ns2=ls1;
                if(max(mids1, lmids1+l)<max(lmids1, mids1+l))
                    nmid=mid, nmids1=mids1, nmids2=lmids1+l;
                else
                    nmid=lmid, nmids1=mids1+l, nmids2=lmids1;
            }
            if(mids1>mids2 && lmids2>lmids1){
                ns1=s1, ns2=ls2;
                if(max(mids1, lmids2+l)<max(lmids2, mids1+l))
                    nmid=mid, nmids1=mids1, nmids2=lmids2+l;
                else
                    nmid=lmid, nmids1=mids1+l, nmids2=lmids2;
            }
            if(mids2>mids1 && lmids1>lmids2){
                ns1=s2, ns2=ls1;
                if(max(mids2, lmids1+l)<max(lmids1, mids2+l))
                    nmid=mid, nmids1=mids2, nmids2=lmids1+l;
                else
                    nmid=lmid, nmids1=mids2+l, nmids2=lmids1;
            }
            if(mids2>mids1 && lmids2>lmids1){
                ns1=s2, ns2=ls2;
                if(max(mids2, lmids2+l)<max(lmids2, mids2+l))
                    nmid=mid, nmids1=mids2, nmids2=lmids2+l;
                else
                    nmid=lmid, nmids1=mids2+l, nmids2=lmids2;
            }
            lmid=nmid, lmids1=nmids1, lmids2=nmids2, ls1=ns1, ls2=ns2;
        }
        //cout<<ls1<<" "<<ls2<<" "<<dl<<" "<<lmids1<<" "<<lmids2<<"\n";

    }
    return dl;
}
/*int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int N, M, L, CA, CB, CT;
    vector<int>A, B, T;
    cin>>N>>M>>L;
    for(int i=1; i<=M; i++){
        cin>>CA>>CB>>CT;
        A.pb(CA), B.pb(CB), T.pb(CT);
    }
    cout<<travelTime(N, M, L, A, B, T)<<"\n";

}
*/

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:62:28: warning: 'lmids2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   62 |             if(mids1>mids2 && lmids2>lmids1){
      |                ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
dreaming.cpp:62:28: warning: 'lmids1' may be used uninitialized in this function [-Wmaybe-uninitialized]
dreaming.cpp:48:9: warning: 'ls1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   48 |         if(ls1==-1){
      |         ^~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 0 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23