1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

#define DH(x) x

#define MAX 150010
#define MAX2 75010

///////////////////////////////////////hash mapa
//#define MAP_SIZE   100003
//#define MAP_SIZE   200009
//#define MAP_SIZE    50021
#define MAP_SIZE  2000003
#define DATA_SIZE  MAX

struct Data {
    int x,y;
    int on;
    int next;
};

//data starts at data[1]
Data mdata[DATA_SIZE];
int data_size = 1;

int hashMap[MAP_SIZE];
int map_size; //needed only for benchmarking

int h_col=0;

inline int mhash(long long x, long long y) {
    return (y*7000003+x*50021)  % MAP_SIZE;
}

void put(int idx) {
    int h = mhash(mdata[idx].x, mdata[idx].y);
    DH(if(hashMap[h]) h_col++;)
    mdata[idx].next = hashMap[h];
    hashMap[h] = idx;
}

int get(int x, int y) {
    int idx = hashMap[mhash(x,y)];
    while (idx != 0 && (mdata[idx].x != x || mdata[idx].y != y))
        idx = mdata[idx].next;
    return idx;
}
///////////////////////////////////////////////////

#define D(x)

int n,m,k,q;
vector<pair<int, int>> Q;
int visit = 1;

vector<int> to_remove;

int removed_[MAX];
static bool removed(int i) {
    return removed_[i];
}
static void clear_removed() {
    for(int i=0;i<data_size;i++) {
        removed_[i] = 0;
    }
}
static void set_removed(int i) {
    removed_[i] = 1;
}


static bool exists(int i) {
    return i != 0 && mdata[i].on && !removed(i);
}

static bool is_removable(int idx) {
    int x = mdata[idx].x,y = mdata[idx].y;
    int idxL = get(x+1,y);
    int idxR = get(x-1,y);
    int idxU = get(x,y+1);
    int idxD = get(x,y-1);
    D(printf("is_removable: (%d,%d) %d %d %d %d\n",x,y, idxL,idxR,idxU,idxD);)
    if(!exists(idxL) && !exists(idxR)) {
        if(exists(idxU)) to_remove.push_back(idxU);
        if(exists(idxD)) to_remove.push_back(idxD);
        return true;
    }
    if(!exists(idxU) && !exists(idxD)) {
        if(exists(idxL)) to_remove.push_back(idxL);
        if(exists(idxR)) to_remove.push_back(idxR);
        return true;
    }

    return false;
}


int result = 0;

void resetCalc() {
    result = 0;
    clear_removed();
    for(int i=1;i<data_size;i++) {
        if(exists(i) && is_removable(i)) {
            set_removed(i);
            D(printf("r1:%d,%d\n",mdata[i].x, mdata[i].y);)
            result++;
        }
    }
}

int calc() {
    visit++;
    while(!to_remove.empty()) {
        int i  = to_remove.back();
        to_remove.pop_back();
        if(exists(i) && is_removable(i)) {
            D(printf("r2:%d,%d\n",mdata[i].x, mdata[i].y);)
            set_removed(i);
            result++;
        }
    }
    return result;
}

int resultU[MAX2];

vector<pair<int,int>> point_added;
void removed_point(int i, int idx) {
    int x = mdata[idx].x, y = mdata[idx].y;
    if(removed(idx)) {
        result--;
    } else {
        to_remove.push_back(get(x+1,y));
        to_remove.push_back(get(x-1,y));
        to_remove.push_back(get(x,  y+1));
        to_remove.push_back(get(x,  y-1));
    }
    resultU[i] = calc();
}

void consume_points() {
    if(!point_added.empty()) {
        resetCalc();
        int i = point_added.back().first;
        resultU[i] = calc();
        for(int k=point_added.size()-1;k>=1;k--) {
            int idx = point_added[k].second;
            int i = point_added[k].first;
            mdata[idx].on = 0;
            removed_point(i-1, idx);
        }
        for(int k=0;k<point_added.size();k++) {
            int idx = point_added[k].second;
            mdata[idx].on = 1;
        }
        if(point_added.size() >1) resetCalc();
        point_added.clear();
    }
}

int main() {
    scanf("%d %d %d %d", &n,&m,&k,&q);
    for(int i=0;i<k;i++) {
        int x,y;
        scanf("%d %d", &mdata[data_size].x, &mdata[data_size].y);
        mdata[data_size].on = 1;
        put(data_size++);
    }
    resetCalc();
    resultU[0]=calc();
    int on = 0;
    for(int i=1;i<=q;i++) {
        int x,y;
        scanf("%d %d", &x,&y);
        Q.emplace_back(x,y);
        int idx = get(x,y);
        if(!idx) {
            mdata[data_size].x = x;
            mdata[data_size].y = y;
            on = mdata[data_size].on = 1;
            idx = data_size;
            put(data_size++);
        } else {
            on = (mdata[idx].on ? 0:1);
        }

        if (on) {
            mdata[idx].on = 1;
            point_added.emplace_back(i, idx);
        } else {
            consume_points();
            mdata[idx].on = 0;
            removed_point(i, idx);
        }
    }
    consume_points();
    for(int i=0;i<=q;i++)
        printf("%d\n", resultU[i]);

    DH(fprintf(stderr, "hash_colisions: %d\n",h_col);)
}