codeforces 812B Sagheer, the Hausmeister dp

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参考某大佬的思路：dp[I][0/1]表示已经灭掉第I层的灯，并且在第I层的左/右端

#include<iostream>#include<cstring>#include<algorithm>using namespace std;const int maxn = 20;const int maxm = 110;int L[maxm],R[maxm];int dp[maxn][2];int main(){int n,m;char s[maxm];//freopen("in.txt","r",stdin);while(cin>>n>>m){int mx=1<<30;for(int i=1;i<=n;i++){L[i]=1e5;R[i]=-1;cin>>s;for(int j=0;j<m+2;j++){if(s[j]=='1'){L[i]=min(L[i],j);R[i]=max(R[i],j);mx=min(mx,i);}}if(L[i]==1e5)L[i]=0,R[i]=m+1;}int ans=0;for(int i=n;i>=mx;i--){if(L[i]==0)//i层为空 {if(i==n){dp[i][0]=0,dp[i][1]=m+1;}else{dp[i][0]=dp[i+1][0]+1;dp[i][1]=dp[i+1][1]+1;}continue;}if(i==mx){ans=min(dp[i+1][0]+1+R[i],dp[i+1][1]+1+(m+1)-L[i]);continue;}if(i==n){dp[i][0]=R[i]*2;dp[i][1]=m+1;continue;}dp[i][0]=min(dp[i+1][0]+2*R[i]+1,dp[i+1][1]+m+2);//灭掉 当前层灯dp[i][1]=min(dp[i+1][0]+m+2,dp[i+1][1]+2*(m+1-L[i])+1);}if(mx==n){ans=R[n];}cout<<ans<<endl;}}

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