01 backpack
Given n items, a backpack with a capacity of m. Each item has two attributes, vi is value, wi is weight, and each item can only be used once.
int main()
{
int v[110], w[110];
int f[110];
int n, m;
cin >> n >> m;
for(int i = 1; i <= n; i ++) cin >> v[i] >> w[i];
for(int i = 1; i <= n; i ++)
for(int j = m; j >= v[i]; j --)
f[j] = max(f[j], f[j - v[i]] + w[i]);
cout << f[m] << endl;
}
Complete backpack
Given n items, a backpack with a capacity of m. Each item has two attributes, vi is value, wi is weight, and each item can be used multiple times.
int main() {
int v[110], w[110];
int f[110];
int n, m;
cin >> n >> m;
for (int i = 1; i <= n; i++) cin >> v[i] >> w[i];
for (int i = 1; i <= n; i++)
for (int j = v[i]; j <= m; j++)
f[j] = max(f[j], f[j - v[i]] + w[i]);
cout << f[m] << endl;
}
Multiple backpack
Given n items, a backpack with a capacity of m. Each item has two attributes, vi is value, wi is weight, and each item can be used a specified number of times.
int main()
{
int v[2010], w[2010];
int f[2010];
int n, m;
int cnt = 0;
cin >> n >> m;
for(int i = 1; i <= n; i ++)
{
int a, b, s;
cin >> a >> b >> s;
int k = 1;
while(k <= s)
{
cnt ++;
v[cnt] = a * k;
w[cnt] = b * k;
s -= k;
k *= 2;
}
if(s > 0)
{
cnt ++;
v[cnt] = a * s;
w[cnt] = b * s;
}
}
n = cnt;
for(int i = 1; i <= n; i ++)
for(int j = m; j >= v[i]; j --)
f[j] = max(f[j], f[j - v[i]] + w[i]);
cout << f[m] << endl;
}