Submission #72557

#	Time	Username	Problem	Language	Result	Execution time	Memory
72557		yusufake	Dreaming (IOI13_dreaming)	C++98	100 / 100	108 ms	16376 KiB

dreaming

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

#define pb push_back
#define mp make_pair
#define st first
#define nd second
#define NN 100005

vector < pair<int,int> > V[NN];
int H[NN],M[NN],node[NN],M2[NN],mn,ss;

void f(int x){
    H[x] = 1;
    int t;
    for(int i=0; i<V[x].size(); i++){
        if(H[ V[x][i].st ]) continue;
        f(V[x][i].st);
        t = M[ V[x][i].st ] + V[x][i].nd;
        if(M[x] < t) { M2[x] = M[x]; M[x] = t; node[x] = V[x][i].st; }
        else if(M2[x] < t) M2[x] = t;
    }
    ss = max(ss , M[x] + M2[x]);
}
void g(int x, int p, int t){
    mn = min(mn , max(M[x] , t));
    for(int i=0; i<V[x].size(); i++){
        if(V[x][i].st == p) continue;
        int a = max(t , node[x] == V[x][i].st ? M2[x] : M[x]);
        g(V[x][i].st , x , a + V[x][i].nd);
    }
}

int travelTime(int n, int m, int l, int *A, int *B, int *T){
    int t,i,x,xx,xxx;
    for(i=0;i<m;i++){
        V[ A[i] ].pb(mp(B[i],T[i]));
        V[ B[i] ].pb(mp(A[i],T[i]));
    }
    x=xx=xxx=-1000000009;
    for(i=0;i<n;i++){
        if(H[i]) continue;
        mn = 1e9;
        f(i);
        g(i,-1,0);
        //cout << i << " " << x << " " << mn << " ss\n";
        if(x < mn){ xxx = xx; xx = x; x = mn; }
        else if(xx < mn) { xxx = xx; xx = mn; }
        else if(xxx < mn) {  xxx = mn; }
    }
    return max(ss , max(x+xx+l , xx+xxx+l+l));
}

Compilation message (stderr)

dreaming.cpp: In function 'void f(int)':
dreaming.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<V[x].size(); i++){
                  ~^~~~~~~~~~~~
dreaming.cpp: In function 'void g(int, int, int)':
dreaming.cpp:28:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<V[x].size(); i++){
                  ~^~~~~~~~~~~~
dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:36:9: warning: unused variable 't' [-Wunused-variable]
     int t,i,x,xx,xxx;
         ^

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