Submission #1730878

---

Source Code Expand

// see https://gist.github.com/LumaKernel/ff55d49ee1af69b7388f15b707e75c15
#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <complex>
#include <random>
#include <iomanip>

using namespace std;

typedef long long ll;
typedef pair<int, int> P;
typedef vector<int> VI;
typedef vector<P> VP;

#define omajinai ios::sync_with_stdio(false);cin.tie(0)

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,a,b) for(int i=(b)-1;i>=(a);--i)
#define RREP(i,n) RFOR(i,0,n)

#define LFOR(i,a,b) for(ll i=(a);i<(b);++i)
#define RLFOR(i,b,a) for(ll i=(b)-1;i>=(a);--i)

#define ALL(a) (a).begin(),(a).end()
#define UNIQUE(a) (a).erase(unique((a).begin(),(a).end()),(a).end())
#define MP make_pair
#define PB push_back
#define EACH(i,c) REP(i,(int)(c).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

#define dump(x) cerr << "[L " << __LINE__ << "] " << #x << " = " << (x) << "\n";
#define dump2(x,y) cerr << "[L " << __LINE__ << "] " << #x << " = " << (x)\
			<< " , " << #y << " = " << (y) << "\n";

const int INF = 1e9;
const double EPS = 1e-10;
const int _N = 2e5 + 100;

int n,m;
ll k;
string s;

struct BIT{
	int data[_N];
	int n;
	void init(int n){
		this->n = n;
		REP(i, n+1)data[i] = 0;
	}
	void add(int i, int x){
		i++;
		while(i<=n){
			data[i] += x;
			i += i&-i;
		}
	}
	int sum(int i){
		i++;
		int s = 0;
		while(i>=1){
			s += data[i];
			i -= i&-i;
		}
		return s;
	}
};

BIT letters[26];

int main() {
	cin >> s;
	n = s.size();

	ll ans = 1;

	REP(i, 26) letters[i].init(n);
	REP(i, n) letters[s[i]%26].add(i, 1);

	FOR(i, 1, n){
		ans += i-letters[s[i]%26].sum(i-1);
	}

	cout << ans;
	cout << endl;
}

Submission Info

Judge Result