delete pics to save space

2.1354.cpp

@@ -0,0 +1,66 @@
+#include<cstdio>
+#include<cstring>
+#include<vector>
+using namespace std;
+struct Tree
+{
+	double L,R;
+	Tree():L(0),R(0){}
+};
+const int maxn=6;
+int n,vis[1<<maxn];
+double r,w[maxn],sum[1<<maxn];
+vector<Tree> tree[1<<maxn];
+void dfs(int subset)
+{
+	if(vis[subset]) return;
+	vis[subset]=true;
+	bool have_children=false;
+	for(int left=(subset-1)&subset;left;left=(left-1)&subset)
+	{
+		have_children=true;
+		int right=subset^left;
+		double d1=sum[right]/sum[subset];
+		double d2=sum[left]/sum[subset];
+		dfs(left);
+		dfs(right);
+		for(int i=0;i<tree[left].size();i++)
+			for(int j=0;j<tree[right].size();j++)
+			{
+				Tree t;
+				t.L=max(tree[left][i].L+d1,tree[right][j].L-d2);
+				t.R=max(tree[right][j].R+d2,tree[left][i].R-d1);
+				if(t.L+t.R<r) tree[subset].push_back(t);
+			}
+	}
+	if(!have_children) tree[subset].push_back(Tree());
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	int T;
+	scanf("%d",&T);
+	while(T--)
+	{
+		scanf("%lf%d",&r,&n);
+		for(int i=0;i<n;i++) scanf("%lf",&w[i]);
+		for(int i=0;i<(1<<n);i++)
+		{
+			sum[i]=0;
+			tree[i].clear();
+			for(int j=0;j<n;j++)
+				if(i&(1<<j)) sum[i] += w[j];
+		}
+		int root=(1<<n)-1;
+		memset(vis,0,sizeof(vis));
+		dfs(root);
+		double ans=-1;
+		for(int i=0;i<tree[root].size();i++)
+			ans=max(ans,tree[root][i].L+tree[root][i].R);
+		if(ans!=-1) printf("%.10lf\n",ans);
+		else printf("-1\n");
+	}
+	return 0;
+}