1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
#include "bits/stdc++.h" // Tomasz Nowak
using namespace std;     // University of Warsaw
using LL = long long;
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
#define ssize(x) int(x.size())
template<class A, class B> auto& operator<<(ostream &o, pair<A, B> p) {
	return o << '(' << p.first << ", " << p.second << ')';
}
template<class T> auto operator<<(ostream &o, T x) -> decltype(x.end(), o) {
	o << '{'; int i = 0; for(auto e : x) o << (", ")+2*!i++ << e; return o << '}';
}
#ifdef DEBUG
#define debug(x...) cerr << "[" #x "]: ", [](auto... $) {((cerr << $ << "; "), ...); }(x), cerr << '\n'
#else
#define debug(...) {}
#endif

ostream& operator<<(ostream &o, string s) {
	return o << s.data();
}

int main() {
	cin.tie(0)->sync_with_stdio(0);

	string in;
	cin >> in;
	int n = ssize(in);
	LL answer = 0;
	{
		map<pair<int, int>, int> m = {{{0, 0}, 1}};
		array bal = {0, 0, 0};
		for(char c : in) {
			++bal[c - 'a'];
			pair p = {bal[1] - bal[0], bal[2] - bal[0]};
			debug(c, p, m);
			answer += m[p]++;
		}
	}

	for(char split_by : {'a', 'b', 'c'}) {
		vector<string> splitted = {""};
		for(char c : in)
			if(c == split_by and splitted.back().size())
				splitted.emplace_back();
			else if(c != split_by)
				splitted.back() += c;
		for(string s : splitted) {
			map<int, int> m = {{0, 1}};
			array bal = {0, 0};
			for(char c : s) {
				++bal[c == 'a' or (c == 'b' and split_by == 'a') ? 0 : 1];
				int p = bal[1] - bal[0];
				debug(s, c, p, m);
				answer += m[p]++;
			}
		}
	}

	for(char only : {'a', 'b', 'c'}) {
		int combo = 0;
		for(char c : in)
			if(c == only) {
				++combo;
				answer += combo;
			}
			else
				combo = 0;
	}
	cout << answer << '\n';
}