5ab1c29c
 tangwang
first commit
|
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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
#include <iostream>
#include <fstream>
#include <utility>
#include <string>
#include <map>
#include <set>
#include <vector>
#include <algorithm>
#include <functional>
#include <string.h>
#include <time.h>
#include <unordered_map>
#include <iterator>
#include <queue>
#include <numeric>
#include "utils.h"
#include "BitMap.h"
int max_sim_list_len = 300;
using namespace std;
typedef unsigned long long item_id_t; // 定义64位无符号整型作为item ID
// 比较函数，用于排序时按item_id_t来比较
bool compare_i2ulist_map_iters2(const unordered_map<item_id_t, vector<int>>::const_iterator &a,
const unordered_map<item_id_t, vector<int>>::const_iterator &b) {
return a->first < b->first;
}
// 比较函数，用于sim_list排序
bool compare_pairs2(const pair<item_id_t, float> &a, const pair<item_id_t, float> &b) {
return a.second > b.second;
}
int main(int argc, char *argv[]) {
float alpha = 0.5;
float threshold = 0.5;
int show_progress = 0;
if (argc < 4) {
cerr << "usage " << argv[0] << " alpha threshold show_progress(0/1)" << endl;
return -1;
}
alpha = atof(argv[1]);
threshold = atof(argv[2]);
show_progress = atoi(argv[3]);
cerr << currentTimetoStr() << " start... " << endl;
cerr << " alpha " << alpha << endl;
cerr << " threshold " << threshold << endl;
unordered_map<item_id_t, vector<int>> i2u_map;
i2u_map.reserve(160000);
string line_buff;
const string delimiters(",");
vector<string> field_segs;
vector<vector<item_id_t>> groups; // Changed to store item_id_t
groups.reserve(2000000);
vector<item_id_t> item_list;
vector<int> items_intersection_buffer;
vector<int> users_intersection_buffer;
users_intersection_buffer.reserve(2000);
pair<item_id_t, vector<int>> pair_entry;
pair<unordered_map<item_id_t, vector<int>>::iterator, bool> ins_i2u_ret;
while (getline(cin, line_buff)) {
// 格式是一个json，所以要把开头和结尾的括号去掉
line_buff.erase(0, line_buff.find_first_not_of("{"));
line_buff.erase(line_buff.find_last_not_of("}") + 1);
field_segs.clear();
split(field_segs, line_buff, delimiters);
item_list.clear();
for (size_t i = 0; i < field_segs.size(); i++) {
const char *seg_pos = strchr(field_segs[i].c_str(), ':');
if (seg_pos == NULL || (seg_pos - field_segs[i].c_str() >= field_segs[i].length())) break;
float value = atof(seg_pos + 1);
if (value > threshold) {
// 开头有一个双引号
item_id_t item_id = strtoull(field_segs[i].c_str() + 1, NULL, 10);
item_list.push_back(item_id);
}
}
if (item_list.size() < 2) continue;
// 排序
sort(item_list.begin(), item_list.end());
// append本次的itemlist
int idx = groups.size();
groups.push_back(item_list); // item_list is now of type item_id_t
// 合入i2u索引
for (vector<item_id_t>::const_iterator iter = item_list.begin(); iter != item_list.end(); ++iter) {
pair_entry.first = *iter;
ins_i2u_ret = i2u_map.insert(pair_entry);
ins_i2u_ret.first->second.push_back(idx);
}
}
int items_num = i2u_map.size();
int users_num = groups.size();
cerr << currentTimetoStr() << " items num: " << i2u_map.size() << endl;
cerr << currentTimetoStr() << " users num: " << groups.size() << endl;
cerr << currentTimetoStr() << " sort.." << endl;
vector<unordered_map<item_id_t, vector<int>>::const_iterator> sorted_i_ulist_pairs;
for (unordered_map<item_id_t, vector<int>>::iterator iter = i2u_map.begin(); iter != i2u_map.end(); ++iter) {
sorted_i_ulist_pairs.push_back(iter);
sort(iter->second.begin(), iter->second.end());
}
cerr << currentTimetoStr() << " sort finished" << endl;
sort(sorted_i_ulist_pairs.begin(), sorted_i_ulist_pairs.end(), compare_i2ulist_map_iters2);
if (items_num < 2) return -1;
vector<pair<item_id_t, float>> sim_list_buff;
unordered_map<item_id_t, vector<pair<item_id_t, float>>> sim_matrix;
sim_matrix.reserve(items_num);
int idx = 0;
BitMap user_bm(users_num);
bool use_bitmap;
vector<int> sim_list_len_statis;
sim_list_len_statis.resize(max_sim_list_len + 1);
for (int i = 1; i < sorted_i_ulist_pairs.size(); ++i) {
unordered_map<item_id_t, vector<int>>::const_iterator pair_i = sorted_i_ulist_pairs[i];
if (show_progress) {
fprintf(stderr, "\r%d of %d", idx++, items_num);
}
sim_list_buff.clear();
use_bitmap = pair_i->second.size() > 50;
if (use_bitmap) {
for (vector<int>::const_iterator iter_pair_i = pair_i->second.begin(); iter_pair_i != pair_i->second.end(); ++iter_pair_i) {
user_bm.Set(*iter_pair_i);
}
}
for (int j = 0; j < i; ++j) {
unordered_map<item_id_t, vector<int>>::const_iterator pair_j = sorted_i_ulist_pairs[j];
users_intersection_buffer.clear();
if (use_bitmap) {
for (vector<int>::const_iterator iter_pair_j = pair_j->second.begin(); iter_pair_j != pair_j->second.end(); ++iter_pair_j) {
if (user_bm.Existed(*iter_pair_j)) {
users_intersection_buffer.push_back(*iter_pair_j);
}
}
} else {
set_intersection(pair_i->second.begin(), pair_i->second.end(), pair_j->second.begin(), pair_j->second.end(), back_inserter(users_intersection_buffer));
}
if (users_intersection_buffer.size() < 2) continue;
float sim_of_item_i_j = 0.0;
for (vector<int>::const_iterator user_i = users_intersection_buffer.begin() + 1;
user_i != users_intersection_buffer.end();
++user_i) {
const vector<item_id_t> &item_list_of_user_i = groups[*user_i];
for (vector<int>::const_iterator user_j = users_intersection_buffer.begin();
user_j != user_i;
++user_j) {
const vector<item_id_t> &item_list_of_user_j = groups[*user_j];
items_intersection_buffer.clear();
set_intersection(item_list_of_user_i.begin(), item_list_of_user_i.end(), item_list_of_user_j.begin(), item_list_of_user_j.end(), back_inserter(items_intersection_buffer));
sim_of_item_i_j += 1.0 / (alpha + items_intersection_buffer.size());
}
}
sim_list_buff.push_back(make_pair(pair_j->first, sim_of_item_i_j));
}
sim_matrix[pair_i->first] = sim_list_buff;
for (auto &p : sim_list_buff) {
sim_matrix[p.first].push_back(make_pair(pair_i->first, p.second));
}
if (use_bitmap) {
for (vector<int>::const_iterator iter_pair_i = pair_i->second.begin(); iter_pair_i != pair_i->second.end(); ++iter_pair_i) {
user_bm.ResetRoughly(*iter_pair_i);
}
}
}
for (auto &p : sim_matrix) {
vector<pair<item_id_t, float>> &sim_list = p.second;
int sim_list_len = p.second.size();
if (sim_list_len > 0) {
sort(sim_list.begin(), sim_list.end(), compare_pairs2);
cout << p.first << "\t" << sim_list[0].first << ":" << sim_list[0].second;
if (sim_list_len > max_sim_list_len) {
sim_list_len = max_sim_list_len;
}
sim_list_len_statis[sim_list_len] += 1;
for (int i = 1; i < sim_list_len; i++) {
cout << ',' << sim_list[i].first << ':' << sim_list[i].second;
}
cout << endl;
}
}
int sum_groups = accumulate(sim_list_len_statis.begin(), sim_list_len_statis.end(), 0);
cerr << currentTimetoStr() << " write sim matrix finished" << endl;
cerr << currentTimetoStr() << " print stats info of sim matrix... " << sim_list_len_statis.size() << endl;
cerr << currentTimetoStr() << " total keys: " << sum_groups << endl;
int accumulate = 0;
for (int i = sim_list_len_statis.size() - 1; i >= 0; i--) {
accumulate += sim_list_len_statis[i];
fprintf(stderr, "simlist_len %4d, num %4d, accumulate %6d accumulated_rate %5.2f%%\n",
i, sim_list_len_statis[i], accumulate, 100.0 * accumulate / sum_groups);
}
return 0;
}
|