【？】串联电阻 [高精度][动态规划-完全背包]

串联电阻

高精+完全背包

核心

for(int i=1;i<=n;++i)
for(int j=1;j<=mt;++j)
if(j-v[i]>=0) ans[j]=ans[j]+ans[j-v[i]];

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define rg register
const int base=10000,power=4;
const int N=30;
ll n,v[N],tt,t[2005],mt;int cnt;
template<class t>void rd(t &x)
{
    x=0;int w=0;char ch=0;
    while(!isdigit(ch)) w|=ch=='-',ch=getchar();
    while(isdigit(ch)) x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
    x=w?-x:x;
}
struct node{
    int a,b,c;
    bool operator <(const node x) const{return c<x.c;}
}e[N];
 
struct num{
    int a[100];
    num(){memset(a,0,sizeof(a));}
    num(int x)
    {
        memset(a,0,sizeof(a));
        int t=0;
        while(x)
        {
            a[++t]=x%base;
            x/=base;
        }
        a[0]=t;
    }
    void add(int k) {if(k||a[0]) a[++a[0]]=k;}
    void re() {reverse(a+1,a+1+a[0]);}
    void print()
    {
        printf("%d",a[a[0]]);
        for(rg int i=a[0]-1;i>0;--i)
        printf("%0*d",power,a[i]);
        printf("
");
    }
}p,pai;
 
bool operator <(const num &p,const num &q)
{
    if(p.a[0]<q.a[0]) return 1;
    if(p.a[0]>q.a[0]) return 0;
    for(rg int i=p.a[0];i>0;--i)
    if(p.a[i]!=q.a[i]) return p.a[i]<q.a[i];
    return 0;
}
 
num operator +(const num &p,const num &q)
{
    num c;
    c.a[0]=max(p.a[0],q.a[0]);
    for(rg int i=1;i<=c.a[0];++i)
    {
        c.a[i]+=p.a[i]+q.a[i];
        c.a[i+1]+=c.a[i]/base,c.a[i]%=base;
    }
    if(c.a[c.a[0]+1]) ++c.a[0];
    return c;
}
 
int main()
{
    //freopen("in.txt","r",stdin);
    while(scanf("%lld",&n)==1&&n)
    {
        memset(v,0,sizeof(v));
        memset(t,0,sizeof(t));
        num ans[2005];
        ans[0]=num(1),cnt=0,mt=0;
        for(rg ll i=1;i<=n;++i) rd(v[i]);
        while(scanf("%lld",&tt)==1&&tt) t[++cnt]=tt,mt=max(mt,tt);
        for(rg ll i=1;i<=n;++i)
        for(rg ll j=1;j<=mt;++j)
        {
            if(j-v[i]>=0) ans[j]=ans[j]+ans[j-v[i]];
        }
        for(ll i=1;i<=cnt;++i) ans[t[i]].print();
    }
    return 0;
}