【HDOJ】4775 Infinite Go

其实是一道模拟题，并查集用来优化。还可以的一道题目。

/* 4775 */
#include <iostream>
#include <sstream>
#include <string>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <deque>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <climits>
#include <cctype>
#include <cassert>
#include <functional>
#include <iterator>
#include <iomanip>
using namespace std;
//#pragma comment(linker,"/STACK:102400000,1024000")

#define sti                set<int>
#define stpii            set<pair<int, int> >
#define mpii            map<int,int>
#define vi                vector<int>
#define pii                pair<int,int>
#define vpii            vector<pair<int,int> >
#define rep(i, a, n)     for (int i=a;i<n;++i)
#define per(i, a, n)     for (int i=n-1;i>=a;--i)
#define clr                clear
#define pb                 push_back
#define mp                 make_pair
#define fir                first
#define sec                second
#define all(x)             (x).begin(),(x).end()
#define SZ(x)             ((int)(x).size())
#define lson            l, mid, rt<<1
#define rson            mid+1, r, rt<<1|1

const int maxn = 10005;
map<pii, int> id;
map<pii, bool> visit;
map<pii, int>::iterator iter;
int X[maxn], Y[maxn];
int sz[maxn], fa[maxn];
int dir[4][2] = {
    -1,0, 1,0, 0,-1, 0,1
};
int n;

int find(int x) {
    if (x == fa[x])
        return x;
    
    return fa[x] = find(fa[x]);
}

bool judge(int x, int y) {
    return x<=0 || y<=0;
}

void remove(int bx, int by, int uid) {
    queue<pii> Q;
    int x, y;
    pii p(bx, by), pp;
    
    visit.clr();
    Q.push(p);
    visit[p] = true;
    
    while (!Q.empty()) {
        p = Q.front();
        Q.pop();
        
        // remove from the id
        iter = id.find(p);
        fa[iter->sec] = iter->sec;
        sz[iter->sec] = 0;
        id.erase(iter);
        
        rep(j, 0, 4) {
            x = p.fir + dir[j][0];
            y = p.sec + dir[j][1];
            if (judge(x, y))
                continue;
            
            pp.fir = x;
            pp.sec = y;
            if (visit[pp])
                continue;
            
            iter = id.find(pp);
            if (iter == id.end())
                continue;
            
            if ((iter->sec&1) ^ uid) {
                int f = find(iter->sec);
                ++sz[f];
            } else {
                visit[pp] = true;
                Q.push(pp);
            }
        }
    }
}

void solve() {
    rep(i, 0, n+1)
        fa[i] = i;
    memset(sz, 0, sizeof(sz));
    id.clr();
    
    int vac, x, y;
    int xx, yy;
    pii p;
    
    rep(i, 1, n+1) {
        p.fir = x = X[i];
        p.sec = y = Y[i];
        id[p] = i;
        vac = 0;
        rep(j, 0, 4) {
            xx = x + dir[j][0];
            yy = y + dir[j][1];
            if (judge(xx, yy))
                continue;
            
            iter = id.find(mp(xx, yy));
            if (iter == id.end()) {
                ++vac;
            } else {
                int f = find(iter->sec);
                --sz[f];
            }
        }
        sz[i] = vac;
        rep(j, 0, 4) {
            xx = x + dir[j][0];
            yy = y + dir[j][1];
            if (judge(xx, yy))
                continue;
            
            iter = id.find(mp(xx, yy));
            if (iter == id.end())
                continue;
            
            if ((iter->sec & 1) ^ (i & 1)) {
                // delete enemy
                int fx = find(iter->sec);
                if (sz[fx] == 0) {
                    remove(xx, yy, iter->sec&1);
                }
                
            } else {
                // link self
                int fx = find(iter->sec);
                int fy = find(i);
                if (fx != fy) {
                    fa[fx] = fy;
                    sz[fy] += sz[fx];
                }
            }
        }
        
        int f = find(i);
        if (sz[f] == 0) {
            remove(x, y, i&1);
        }
    }
    
    int ansa, ansb;
    
    ansa = ansb = 0;
    visit.clr();
    per(i, 1, n+1) {
        p.fir = X[i];
        p.sec = Y[i];
        iter = id.find(p);
        if (iter==id.end() || visit[p])
            continue;
        
        visit[p] = true;
        if (iter->sec & 1)
            ++ansa;
        else
            ++ansb;
    }
    
    printf("%d %d
", ansa, ansb);
}

int main() {
    ios::sync_with_stdio(false);
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
        freopen("data.out", "w", stdout);
    #endif
    
    int t;
    
    scanf("%d", &t);
    while (t--) {
        scanf("%d", &n);
        rep(i, 1, n+1)
            scanf("%d %d", &X[i], &Y[i]);
        solve();
    }
    
    #ifndef ONLINE_JUDGE
        printf("time = %d.
", (int)clock());
    #endif
    
    return 0;
}

数据发生器。

from random import randint, shuffle
import shutil
import string


def GenDataIn():
    with open("data.in", "w") as fout:
        t = 10
        fout.write("%d
" % t)
        bound = 10**2
        for tt in xrange(t):
            n = randint(1000, 5000)
            fout.write("%d
" % n)
            d = dict()
            for i in xrange(n):
                while True:
                    x = randint(1, bound)
                    y = randint(1, bound)
                    tpl = (x, y)
                    if tpl not in d:
                        d[tpl] = True
                        break
                fout.write("%d %d
" % (x, y))
                
                
def MovDataIn():
    desFileName = "F:eclipse_prjworkspacehdojdata.in"
    shutil.copyfile("data.in", desFileName)

    
if __name__ == "__main__":
    GenDataIn()
    MovDataIn()