Submission #1119419

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119419		kiethm07	Cats or Dogs (JOI18_catdog)	C++11	38 / 100	3025 ms	12088 KiB

catdog

#include <bits/stdc++.h>
 
#define pii pair<int,int>
#define iii pair<int,pii>
#define fi first
#define se second
 
#define vi vector<int>
#define all(x) x.begin(),x.end()
 
#define TEXT "CatsorDogs"
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
 
const int inf = 1e9 + 7;
const ld eps = 1e-8;
const double pi = acos(-1);
const int N = 1e5 + 5;
 
int n;
vector<int> a[N];
int f[N], g[N];
int preF[N], preG[N];
int type[N];
int pa[N];
 
void dfs(int u,int p){
    for (int i = 0; i < a[u].size(); i++){
        int v = a[u][i];
        if (v == p) continue;
        pa[v] = u;
        dfs(v,u);
    }
}
 
void brute(int u,int p){
    if (type[u] == 0) f[u] = g[u] = 0;
    if (type[u] == 1) f[u] = 0, g[u] = inf;
    if (type[u] == 2) f[u] = inf, g[u] = 0;
    for(int v : a[u]){
        if (v == p) continue;
        brute(v,u);
        if (f[u] != inf) f[u] += min(f[v], g[v] + 1);
        if (g[u] != inf) g[u] += min(f[v] + 1, g[v]);
    }
}
 
void initialize(int N,vector<int> u, vector<int> v){
    n = N;
    for (int i = 0; i < n - 1; i++){
        a[u[i]].push_back(v[i]);
        a[v[i]].push_back(u[i]);
    }
    dfs(1,-1);
}
 
int cat(int u){
    type[u] = 1;
//    brute(1,-1);
    g[u] = inf;
    while(u != 0){
        int p = pa[u];
        ///f[p] += min(f[u], g[u] + 1)
        if (f[p] != inf){
            if (preF[u] <= preG[u] + 1) f[p] += -preF[u] + min(f[u], g[u] + 1);
            else f[p] += -(preG[u] + 1) + min(f[u], g[u] + 1);
        }
        if (g[p] != inf){
            if (preG[u] <= preF[u] + 1) g[p] += -preG[u] + min(f[u] + 1, g[u]);
            else g[p] += -(preF[u] + 1) + min(f[u] + 1, g[u]);
        }
        preF[u] = f[u];
        preG[u] = g[u];
        u = p;
    }
    return min(f[1], g[1]);
}
 
int dog(int u){
    type[u] = 2;
    f[u] = inf;
    while(u != 0){
        int p = pa[u];
        ///f[p] += min(f[u], g[u] + 1)
        if (f[p] != inf){
            if (preF[u] <= preG[u] + 1) f[p] += -preF[u] + min(f[u], g[u] + 1);
            else f[p] += -(preG[u] + 1) + min(f[u], g[u] + 1);
        }
        if (g[p] != inf){
            if (preG[u] <= preF[u] + 1) g[p] += -preG[u] + min(f[u] + 1, g[u]);
            else g[p] += -(preF[u] + 1) + min(f[u] + 1, g[u]);
        }
        preF[u] = f[u];
        preG[u] = g[u];
        u = p;
    }
//    brute(1,-1);
    return min(f[1], g[1]);
}
 
int neighbor(int u){
    type[u] = 0;
    f[u] = g[u] = 0;
    for (int v : a[u]){
        if (v == pa[u]) continue;
        f[u] += min(f[v], g[v] + 1);
        g[u] += min(g[v], f[v] + 1);
    }
    while(u != 0){
        int p = pa[u];
        ///f[p] += min(f[u], g[u] + 1)
        if (f[p] != inf){
            if (preF[u] <= preG[u] + 1) f[p] += -preF[u] + min(f[u], g[u] + 1);
            else f[p] += -(preG[u] + 1) + min(f[u], g[u] + 1);
        }
        if (g[p] != inf){
            if (preG[u] <= preF[u] + 1) g[p] += -preG[u] + min(f[u] + 1, g[u]);
            else g[p] += -(preF[u] + 1) + min(f[u] + 1, g[u]);
        }
        preF[u] = f[u];
        preG[u] = g[u];
        u = p;
    }
//    brute(1,-1);
    return min(f[1], g[1]);
}

Compilation message (stderr)

catdog.cpp: In function 'void dfs(int, int)':
catdog.cpp:32:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for (int i = 0; i < a[u].size(); i++){
      |                     ~~^~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 30 / 30
• Subtask 3: 0 / 62