제출 #116541

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
116541		Runtime_error_	경주 (Race) (IOI11_race)	C++14	100 / 100	960 ms	54040 KiB

race

//IOI 2011 Day1 Problem 2 Race
//Full solutions
#include "race.h"
#include <bits/stdc++.h>
using namespace std;
const int inf=1e6+9;
vector<pair<int,int> > v[inf],add;
bool blocked[inf];
int subtree[inf],level[inf],dis[inf],min_path[inf],parent[inf],n,k;

void dfs_size(int node,int par){

    subtree[node]=1;
    parent[node]=par;
    for(auto o:v[node])
        if(!blocked[o.first] && par!=o.first)
            dfs_size(o.first,node),
            subtree[node]+=subtree[o.first];
}

int dfs_add(int node,int l,int d,int par){

    if(d>k)
        return 1e9+9;

    add.push_back(make_pair(l,d));

    int ret=min_path[k-d]+l;

    for(auto o:v[node])
        if(o.first!=par && !blocked[o.first])
            ret=min(ret,dfs_add(o.first,l+1,d+o.second,node));

        return ret;
}

void dfs_remove(int node,int d,int par){

    if(d>k)
        return ;
    min_path[d]=1e9+9;
    for(auto o:v[node])
        if(!blocked[o.first] && par!=o.first)
            dfs_remove(o.first,d+o.second,node);
}

int solve(int centroid){

    min_path[0]=0;
    int ret=1e9+9;
    for(auto o:v[centroid]){

        if(blocked[o.first])
            continue;

        ret=min(ret,dfs_add(o.first,1,o.second,centroid));
        while(!add.empty())
            min_path[add.back().second]=min(min_path[add.back().second],add.back().first),
            add.pop_back();
    }
    dfs_remove(centroid,0,-1);
    return ret;
}

int create(int start){
    dfs_size(start,-1);

    int centroid=start,best=subtree[start];

    queue<int> q;
    q.push(start);
    while(!q.empty()){
        int u=q.front();
        q.pop();
        int sz=subtree[start]-subtree[u];
        for(auto o:v[u])
            if(!blocked[o.first] && parent[u]!=o.first)
                sz=max(sz,subtree[o.first] ),q.push(o.first);

        if(sz<best)
            best=sz,centroid=u;
    }
    blocked[centroid]=1;

    int ret=solve(centroid);

    for(auto o:v[centroid])
        if(!blocked[o.first])
            ret=min( ret,create( o.first ) );
    return ret;
}


int best_path(int N, int K, int H[][2], int L[]){

    n=N;
    k=K;
    for(int i=0;i<=K;i++)
        min_path[i]=1e9+9;

    for(int i=0;i<N-1;i++){
        int x=H[i][0],y=H[i][1],z=L[i];
        v[x].push_back(make_pair(y,z));
        v[y].push_back(make_pair(x,z));
    }
    int ret=create(0);
    if(ret>N)
        ret=-1;
    return ret;
}

컴파일 시 표준 에러 (stderr) 메시지

race.cpp: In function 'int dfs_add(int, int, int, int)':
race.cpp:30:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(auto o:v[node])
     ^~~
race.cpp:34:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
         return ret;
         ^~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 22 / 22
• Subtask 4: 57 / 57