delete pics to save space

2.12206.cpp

@@ -0,0 +1,60 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=40010;
+const int x=33;
+int n,m,pos;
+unsigned long long H[maxn],xp[maxn],hsh[maxn];
+int rnk[maxn];
+int cmp(int a,int b)
+{
+	return hsh[a]<hsh[b]||(hsh[a]==hsh[b]&&a<b);
+}
+int possible(int L)
+{
+	int c=0;
+	pos=-1;
+	for(int i=0;i<n-L+1;i++)
+	{
+		rnk[i]=i;
+		hsh[i]=H[i]-H[i+L]*xp[L];
+	}
+	sort(rnk,rnk+n-L+1,cmp);
+	for(int i=0;i<n-L+1;i++)
+	{
+		if(i==0||hsh[rnk[i]]!=hsh[rnk[i-1]]) c=0;
+		if(++c>=m) pos=max(pos,rnk[i]);
+	}
+	return pos>=0;
+}
+char s[maxn];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	xp[0]=1;
+	for(int i=1;i<maxn;i++) xp[i]=xp[i-1]*x;
+	while(scanf("%d",&m)==1&&m)
+	{
+		scanf("%s",s);
+		n=strlen(s);
+		H[n]=0;
+		for(int i=n-1;i>=0;i--) H[i]=H[i+1]*x+s[i]-'a';
+		if(!possible(1)) printf("none\n");
+		else
+		{
+			int L=1,R=n+1;
+			while(R-L>1)
+			{
+				int M=(L+R)/2;
+				if(possible(M)) L=M;
+				else R=M;
+			}
+			possible(L);
+			printf("%d %d\n",L,pos);
+		}
+	}
+	return 0;
+}