回答編集履歴
7
追記2
answer
CHANGED
|
@@ -74,4 +74,77 @@
|
|
|
74
74
|
ks.solve();
|
|
75
75
|
ks.output();
|
|
76
76
|
}
|
|
77
|
+
```
|
|
78
|
+
**追記2**
|
|
79
|
+
n個のアイテムをナップサックに入れるか入れないかを 1 か 0 で表すと、
|
|
80
|
+
全列挙とは nビットの数値(00...000～11...111)になります。
|
|
81
|
+
11...111 は、(1<<n) - 1。
|
|
82
|
+
```C++
|
|
83
|
+
#include <iostream>
|
|
84
|
+
#include <fstream>
|
|
85
|
+
#include <vector>
|
|
86
|
+
using namespace std;
|
|
87
|
+
|
|
88
|
+
class Knapsack {
|
|
89
|
+
int n, capa, best_profit, best_weight;
|
|
90
|
+
vector<int> p, w, item, best;
|
|
91
|
+
public:
|
|
92
|
+
bool input(const char* fname) {
|
|
93
|
+
ifstream ifs(fname);
|
|
94
|
+
if (!ifs) return false;
|
|
95
|
+
ifs >> n;
|
|
96
|
+
p.resize(n);
|
|
97
|
+
w.resize(n);
|
|
98
|
+
for (int i = 0; i < n; i++) ifs >> p[i];
|
|
99
|
+
for (int i = 0; i < n; i++) ifs >> w[i];
|
|
100
|
+
ifs >> capa;
|
|
101
|
+
best_profit = 0;
|
|
102
|
+
item.resize(n);
|
|
103
|
+
best.resize(n);
|
|
104
|
+
return true;
|
|
105
|
+
}
|
|
106
|
+
|
|
107
|
+
void solve() {
|
|
108
|
+
int m = 1 << n;
|
|
109
|
+
for (int bp = 0; bp < m; bp++) { // bit pattern
|
|
110
|
+
int profit = 0, weight = 0;
|
|
111
|
+
for (int i = 0; i < n; i++) {
|
|
112
|
+
if (bp>>i & 1) {
|
|
113
|
+
item[i] = 1;
|
|
114
|
+
profit += p[i];
|
|
115
|
+
weight += w[i];
|
|
116
|
+
}
|
|
117
|
+
else item[i] = 0;
|
|
118
|
+
}
|
|
119
|
+
if (weight <= capa && profit > best_profit) {
|
|
120
|
+
best = item;
|
|
121
|
+
best_profit = profit;
|
|
122
|
+
best_weight = weight;
|
|
123
|
+
}
|
|
124
|
+
}
|
|
125
|
+
}
|
|
126
|
+
|
|
127
|
+
void output() {
|
|
128
|
+
cout << "item:";
|
|
129
|
+
for (int i = 0; i < n; i++)
|
|
130
|
+
if (best[i]) cout << " " << i+1;
|
|
131
|
+
cout << "\n" "profit = " << best_profit
|
|
132
|
+
<< " weight = " << best_weight << "\n";
|
|
133
|
+
}
|
|
134
|
+
};
|
|
135
|
+
|
|
136
|
+
int main(int argc, char *argv[])
|
|
137
|
+
{
|
|
138
|
+
if (argc != 2) {
|
|
139
|
+
cout << "usage: " << argv[0] << " file_name\n";
|
|
140
|
+
return 1;
|
|
141
|
+
}
|
|
142
|
+
Knapsack ks;
|
|
143
|
+
if (!ks.input(argv[1])) {
|
|
144
|
+
cout << "can't open " << argv[1] << "\n";
|
|
145
|
+
return 1;
|
|
146
|
+
}
|
|
147
|
+
ks.solve();
|
|
148
|
+
ks.output();
|
|
149
|
+
}
|
|
77
150
|
```
|
6
コードの修正
answer
CHANGED
|
@@ -22,7 +22,7 @@
|
|
|
22
22
|
public:
|
|
23
23
|
bool input(const char* fname) {
|
|
24
24
|
ifstream ifs(fname);
|
|
25
|
-
if (!ifs) false;
|
|
25
|
+
if (!ifs) return false;
|
|
26
26
|
ifs >> n;
|
|
27
27
|
p.resize(n);
|
|
28
28
|
w.resize(n);
|
|
@@ -67,7 +67,10 @@
|
|
|
67
67
|
return 1;
|
|
68
68
|
}
|
|
69
69
|
Knapsack ks;
|
|
70
|
-
if (!ks.input(argv[1]))
|
|
70
|
+
if (!ks.input(argv[1])) {
|
|
71
|
+
cout << "can't open " << argv[1] << "\n";
|
|
72
|
+
return 1;
|
|
73
|
+
}
|
|
71
74
|
ks.solve();
|
|
72
75
|
ks.output();
|
|
73
76
|
}
|
5
クラス名の変更
answer
CHANGED
|
@@ -16,7 +16,7 @@
|
|
|
16
16
|
#include <vector>
|
|
17
17
|
using namespace std;
|
|
18
18
|
|
|
19
|
-
class
|
|
19
|
+
class Knapsack {
|
|
20
20
|
int n, capa, max_profit, max_weight;
|
|
21
21
|
vector<int> p, w, u, best;
|
|
22
22
|
public:
|
|
@@ -66,9 +66,9 @@
|
|
|
66
66
|
cout << "usage: " << argv[0] << " file_name\n";
|
|
67
67
|
return 1;
|
|
68
68
|
}
|
|
69
|
-
|
|
69
|
+
Knapsack ks;
|
|
70
|
-
if (!
|
|
70
|
+
if (!ks.input(argv[1])) return 1;
|
|
71
|
-
|
|
71
|
+
ks.solve();
|
|
72
|
-
|
|
72
|
+
ks.output();
|
|
73
73
|
}
|
|
74
74
|
```
|
4
コードの修正
answer
CHANGED
|
@@ -20,8 +20,6 @@
|
|
|
20
20
|
int n, capa, max_profit, max_weight;
|
|
21
21
|
vector<int> p, w, u, best;
|
|
22
22
|
public:
|
|
23
|
-
DP() : n(-1) { }
|
|
24
|
-
|
|
25
23
|
bool input(const char* fname) {
|
|
26
24
|
ifstream ifs(fname);
|
|
27
25
|
if (!ifs) false;
|
3
コードの修正
answer
CHANGED
|
@@ -37,8 +37,6 @@
|
|
|
37
37
|
return true;
|
|
38
38
|
}
|
|
39
39
|
|
|
40
|
-
bool fail() { return n < 0; }
|
|
41
|
-
|
|
42
40
|
void step(int i, int profit, int weight) {
|
|
43
41
|
if (i == n) {
|
|
44
42
|
if (weight <= capa && profit > max_profit) {
|
2
コードの修正
answer
CHANGED
|
@@ -44,7 +44,7 @@
|
|
|
44
44
|
if (weight <= capa && profit > max_profit) {
|
|
45
45
|
max_profit = profit;
|
|
46
46
|
max_weight = weight;
|
|
47
|
-
|
|
47
|
+
best = u;
|
|
48
48
|
}
|
|
49
49
|
}
|
|
50
50
|
else if (weight <= capa) {
|
1
追記
answer
CHANGED
|
@@ -6,4 +6,73 @@
|
|
|
6
6
|
i は 0～(n-1)、j は 0～(capa-1) でなければなりません。
|
|
7
7
|
dp[n][y] = 0; の n は範囲外であり、y も capa になるので範囲外です。
|
|
8
8
|
これが segmentation fault の原因です。
|
|
9
|
-
w[i] も i は 1～(n-1) でないといけないのに w[n] を参照しています。
|
|
9
|
+
w[i] も i は 1～(n-1) でないといけないのに w[n] を参照しています。
|
|
10
|
+
|
|
11
|
+
**追記**
|
|
12
|
+
関数の引数が多いのは面倒なので、クラスを使ってみました。
|
|
13
|
+
```C++
|
|
14
|
+
#include <iostream>
|
|
15
|
+
#include <fstream>
|
|
16
|
+
#include <vector>
|
|
17
|
+
using namespace std;
|
|
18
|
+
|
|
19
|
+
class DP {
|
|
20
|
+
int n, capa, max_profit, max_weight;
|
|
21
|
+
vector<int> p, w, u, best;
|
|
22
|
+
public:
|
|
23
|
+
DP() : n(-1) { }
|
|
24
|
+
|
|
25
|
+
bool input(const char* fname) {
|
|
26
|
+
ifstream ifs(fname);
|
|
27
|
+
if (!ifs) false;
|
|
28
|
+
ifs >> n;
|
|
29
|
+
p.resize(n);
|
|
30
|
+
w.resize(n);
|
|
31
|
+
for (int i = 0; i < n; i++) ifs >> p[i];
|
|
32
|
+
for (int i = 0; i < n; i++) ifs >> w[i];
|
|
33
|
+
ifs >> capa;
|
|
34
|
+
max_profit = 0;
|
|
35
|
+
u.resize(n);
|
|
36
|
+
best.resize(n);
|
|
37
|
+
return true;
|
|
38
|
+
}
|
|
39
|
+
|
|
40
|
+
bool fail() { return n < 0; }
|
|
41
|
+
|
|
42
|
+
void step(int i, int profit, int weight) {
|
|
43
|
+
if (i == n) {
|
|
44
|
+
if (weight <= capa && profit > max_profit) {
|
|
45
|
+
max_profit = profit;
|
|
46
|
+
max_weight = weight;
|
|
47
|
+
for (i = 0; i < n; i++) best[i] = u[i];
|
|
48
|
+
}
|
|
49
|
+
}
|
|
50
|
+
else if (weight <= capa) {
|
|
51
|
+
u[i] = 0; step(i+1, profit, weight);
|
|
52
|
+
u[i] = 1; step(i+1, profit + p[i], weight + w[i]);
|
|
53
|
+
}
|
|
54
|
+
}
|
|
55
|
+
|
|
56
|
+
void solve() { step(0, 0, 0); }
|
|
57
|
+
|
|
58
|
+
void output() {
|
|
59
|
+
cout << "item:";
|
|
60
|
+
for (int i = 0; i < n; i++)
|
|
61
|
+
if (best[i]) cout << " " << i+1;
|
|
62
|
+
cout << "\n" "profit = " << max_profit
|
|
63
|
+
<< " weight = " << max_weight << "\n";
|
|
64
|
+
}
|
|
65
|
+
};
|
|
66
|
+
|
|
67
|
+
int main(int argc, char *argv[])
|
|
68
|
+
{
|
|
69
|
+
if (argc != 2) {
|
|
70
|
+
cout << "usage: " << argv[0] << " file_name\n";
|
|
71
|
+
return 1;
|
|
72
|
+
}
|
|
73
|
+
DP dp;
|
|
74
|
+
if (!dp.input(argv[1])) return 1;
|
|
75
|
+
dp.solve();
|
|
76
|
+
dp.output();
|
|
77
|
+
}
|
|
78
|
+
```
|