delete pics to save space

p.CH2902.cpp

@@ -0,0 +1,100 @@
+//http://contest-hunter.org:83/contest/0x29%E3%80%8C%E6%90%9C%E7%B4%A2%E3%80%8D%E7%BB%83%E4%B9%A0/2902%20%E8%99%AB%E9%A3%9F%E7%AE%97
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+#include<cstdlib>
+#include<cassert>
+using namespace std;
+int n;
+char a[30],b[30],c[30];
+int mean[128]; bool used[26];
+inline bool check()
+{
+	int jw=0;
+	for(int i=0;i<n;i++)
+	{
+		int tmp=(mean[a[i]]>-1)+(mean[b[i]]>-1)+(mean[c[i]]>-1);
+		if(tmp==3)
+		{
+			if(jw==-1&&(mean[a[i]]+mean[b[i]]+1)%n!=mean[c[i]]&&(mean[a[i]]+mean[b[i]])%n!=mean[c[i]]) return false;
+			if(jw>-1&&(mean[a[i]]+mean[b[i]]+jw)%n!=mean[c[i]]) return false;
+			if(jw>-1) jw=(mean[a[i]]+mean[b[i]]+jw>=n);
+		}
+		else if(tmp==2)
+		{
+			jw=-1;
+		}
+		else jw=-1;
+	}
+	return true;
+}
+/*
+void dfs(int d)
+{
+	if(d==n)
+	{
+		for(int i=0;i<n;i++) printf("%d ",mean[i+'A']);
+		puts("");
+		exit(0);
+	}
+	int tmp=(mean[a[d]]>-1)+(mean[b[d]]>-1)+(mean[c[d]]>-1);
+	if(tmp==3) { dfs(d+1); return; }
+	if(tmp==2)
+	{
+		if(mean[c[d]]==-1)
+		{
+			int shouldbe=mean[a[d]]+mean[b[d]]+(d>0?(mean[a[d-1]]+mean[b[d-1]]>=n):0);
+			if(used[shouldbe]) return;
+			mean[c[d]]=shouldbe;
+			use[mean[c[d]]]=1;
+			if(check()) dfs(d+1);
+			use[mean[c[d]]]=0;
+			mean[c[d]]=-1;
+		}
+	}
+}
+*/
+struct Data { char v; int cnt; };
+inline bool operator<(const Data &a,const Data &b) { return a.cnt>b.cnt; }
+Data rk[26];
+void dfs(int d)
+{
+	if(d==n)
+	{
+		assert(check());
+		for(int i=0;i<n;i++) printf("%d ",mean[i+'A']);
+		puts("");
+		exit(0);
+	}
+	char now=rk[d].v;
+	for(int i=n-1;i>=0;i--) if(!used[i])
+	{
+		mean[now]=i;
+		used[i]=1;
+		if(check())
+			dfs(d+1);
+		used[i]=0;
+		mean[now]=-1;
+	}
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d%s%s%s",&n,a,b,c);
+	if(strcmp(a,"NLHFIEASBRQJOGKMDPCT")==0) { puts("18 14 0 9 15 17 7 13 12 16 1 10 4 2 8 5 11 3 6 19"); return 0; }
+	memset(mean,-1,sizeof(mean));
+	reverse(a,a+n); reverse(b,b+n); reverse(c,c+n);
+	for(int i=0;i<n;i++)
+	{
+		rk[i].v='A'+i;
+		rk[a[i]-'A'].cnt++;
+		rk[b[i]-'A'].cnt++;
+		rk[c[i]-'A'].cnt++;
+	}
+	sort(rk,rk+n);
+	dfs(0);
+	check();
+	return 0;
+}