#AT2520. D - Three Days Ago
D - Three Days Ago
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D - Three Days Ago
Score : $400$ points
Problem Statement
The string 20230322
can be rearranged into 02320232
, which is a repetition of 0232
twice.
Similarly, a string consisting of digits is said to be happy when it can be rearranged into (or already is) a repetition of some string twice.
You are given a string $S$ consisting of digits. Find the number of pairs of integers $(l,r)$ satisfying all of the following conditions.
- $1 \le l \le r \le |S|$. ($|S|$ is the length of $S$.)
- The (contiguous) substring formed of the $l$-th through $r$-th characters of $S$ is happy.
Constraints
- $S$ is a string consisting of digits whose length is between $1$ and $5 \times 10^5$, inclusive.
Input
The input is given from Standard Input in the following format:
Output
Print an integer representing the answer.
20230322
4
We have $S=$ 20230322
.
Here are the four pairs of integers $(l,r)$ that satisfy the condition: $(1,6)$, $(1,8)$, $(2,7)$, and $(7,8)$.
0112223333444445555556666666777777778888888889999999999
185
$S$ may begin with 0
.
3141592653589793238462643383279502884197169399375105820974944
9