【BZOJ1970】[AHOI2005]矿藏编码（模拟）

题面

题解

随便写个高精度模拟一下就完了。
#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

#define ll long long

int n,l,k;char ch[500];

struct BigInt

{

    int s[2000],ws;

    void init(){memset(s,0,sizeof(s));s[ws=1]=0;}

    void output(){for(int i=ws;i;--i)printf("%d",s[i]);puts("");}

	void eql(ll x){init();ws=0;while(x)s[++ws]=x%10,x/=10;}

}ans,P;

BigInt operator+(BigInt a,BigInt b)

{

    int ws=max(a.ws,b.ws);

    for(int i=1;i<=ws;++i)a.s[i]+=b.s[i];

    for(int i=1;i<=ws;++i)a.s[i+1]+=a.s[i]/10,a.s[i]%=10;

    while(a.s[ws+1])++ws,a.s[ws+1]+=a.s[ws]/10,a.s[ws]%=10;

    a.ws=ws;return a;

}

BigInt operator*(BigInt a,BigInt b)

{

    BigInt ret;int ws=a.ws+b.ws;ret.init();

    for(int i=1;i<=a.ws;++i)

        for(int j=1;j<=b.ws;++j)

            ret.s[i+j-1]+=a.s[i]*b.s[j];

    for(int i=1;i<=ws;++i)ret.s[i+1]+=ret.s[i]/10,ret.s[i]%=10;

    while(!ret.s[ws])--ws;

    ret.ws=ws;return ret;

}

void dfs(int K)

{

	++l;

	if(ch[l]=='0')P.eql(1ll<<K),ans=ans+P*P;

	else if(ch[l]=='1');

	else dfs(K-1),dfs(K-1),dfs(K-1),dfs(K-1);

}

int main()

{

	scanf("%d",&k);scanf("%s",ch+1);

	n=strlen(ch+1);dfs(k);

	ans.output();

	return 0;

}