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OI-codes/Gym/104008/M/M.cpp

79 lines
1.3 KiB
C++

#include <iostream>
#include <deque>
#include <string>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 3e5 + 5;
int n, m, p[N], c[N];
long long ans;
bool reversed;
std::string s;
std::deque<int> q;
int lowbit(int x) {
return x & -x;
}
void add(int x, int y) {
for (; x <= n; x += lowbit(x)) c[x] += y;
}
int sum(int x) {
int res = 0;
for (; x; x -= lowbit(x)) res += c[x];
return res;
}
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> p[i];
q.emplace_back(p[i]);
}
for (int i = n; i; i--) {
ans += sum(p[i]);
add(p[i], 1);
}
cout << ans << endl;
cin >> s;
for (char c : s) {
if (c == 'S') {
int u;
if (reversed) {
u = q.back();
q.pop_back();
q.push_front(u);
} else {
u = q.front();
q.pop_front();
q.push_back(u);
}
ans += (n - 2 * u + 1);
} else { // c == 'R'
reversed = !reversed;
ans = static_cast<long long>(n) * (n - 1) / 2 - ans;
}
cout << ans % 10;
}
cout << endl;
return 0;
}