原题传送门
暴力dp
可以用倍增思想, 把物品用二进制分组
比如
这样在复杂度里面可以把一个
优化成
复杂度满足
Code:
#include <bits/stdc++.h>
#define maxn 110
#define maxm 40010
using namespace std;
struct node{
int v, w;
}a[maxm];
int n, W, dp[maxm], tot;
inline int read(){
int s = 0, w = 1;
char c = getchar();
for (; !isdigit(c); c = getchar()) if (c == '-') w = -1;
for (; isdigit(c); c = getchar()) s = (s << 1) + (s << 3) + (c ^ 48);
return s * w;
}
int main(){
n = read(), W = read();
for (int i = 1; i <= n; ++i){
int v = read(), w = read(), m = read(), x = 1;
while (x <= m) a[++tot].v = x * v, a[tot].w = x * w, m -= x, x <<= 1;
if (m) a[++tot].v = m * v, a[tot].w = m * w;
}
for (int i = 1; i <= tot; ++i)
for (int j = W; j >= a[i].w; --j) dp[j] = max(dp[j], dp[j - a[i].w] + a[i].v);
printf("%d\n", dp[W]);
return 0;
}