delete pics to save space

1.3805.cpp

@@ -0,0 +1,32 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=51000005;
+int n,R[maxn],ans;
+char a[maxn],s[maxn<<1];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%s",a); n=strlen(a);
+	s[0]=s[1]='#';
+	for(int i=0;i<n;i++) s[i*2+2]=a[i],s[i*2+3]='#';
+	n=2*n+2;
+	int maxright=0,mid=0;
+	for(int i=1;i<n;i++)
+	{
+		if(i<maxright) R[i]=min(R[mid*2-i],R[mid]+mid-i);
+		else R[i]=1;
+		while(s[i-R[i]]==s[i+R[i]]) ++R[i];
+		if(R[i]+i>maxright) { maxright=R[i]+i; mid=i; }
+	}
+	ans=1;
+	for(int i=0;i<n;i++) ans=max(ans,R[i]-1);
+	printf("%d\n",ans);
+	return 0;
+}
+/*
+orzro
+*/