632B - Alice Bob Two Teams - CodeForces Solution

#include<bits/stdc++.h>
#pragma GCC optimize(2)
using namespace std;

#define int long long
#define ios ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define fi first
#define se second
#define endl "\n"
#define YES return cout << "YES" << endl, void()
#define NO return cout << "NO" << endl, void()
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;
const double PI = acos(-1);
const double eqa = (1+sqrt(5.0))/2.0;
const int mod = 1000000007, inf = 0x3f3f3f3f;
const long long INF = 0x3f3f3f3f3f3f3f3f;
int dx[] = {0, 1, 0, -1, -1, 1, 1, -1};
int dy[] = {1, 0, -1, 0, 1, 1, -1, -1};
int gcd(int x, int y) {return y ? gcd(y, x % y) : x;}
int qmi(int a, int k, int p){int res = 1;while (k){if (k & 1) res = (LL)res * a % p;a = (LL)a * a % p;k >>= 1;}return res;}
int read(){int x = 0, f = 1;char ch = getchar();while (ch < '0' || ch > '9'){if (ch == '-') f = -1; ch = getchar();}
while (ch >= '0' && ch <= '9'){x = x * 10 + ch - '0'; ch = getchar();}return x * f;}

const int N = 200010;

void solve()
{
	int n;
	cin >> n;
	vector<int> a(n + 1, 0);
	for ( int i = 1; i <= n; i ++ ) cin >> a[i];
	string s;
	cin >> s;
	s = ' ' + s;
	vector<int> psa(n + 2, 0), ssa(n + 2, 0), psb(n + 2, 0), ssb(n + 2, 0);
	for ( int i = 1; i <= n; i ++ ) {
		if (s[i] == 'A') {
			psa[i] = psa[i - 1] + a[i];
			psb[i] = psb[i - 1];
		}
		else {
			psb[i] = psb[i - 1] + a[i];
			psa[i] = psa[i - 1];
		}
		// cout << psa[i] << " " << psb[i] << endl;
	}
	for ( int i = n; i >= 1; i -- ) {
		if (s[i] == 'A') {
			ssa[i] = ssa[i + 1] + a[i];
			ssb[i] = ssb[i + 1];
		} else {
			ssb[i] = ssb[i + 1] + a[i];
			ssa[i] = ssa[i + 1];
		}
	}
	int mx = 0;
	for ( int i = 1; i <= n; i ++ ) {
		mx = max(mx, psa[i] - psb[i]);
	}
	for ( int i = n; i >= 1; i -- ) {
		mx = max(mx, ssa[i] - ssb[i]);
	}
	cout << psb[n] + mx << endl;
}

signed main()
{
	ios;
	int t = 1;
	// cin >> t;
	while (t --)
	{
		solve();
	}
	return 0;
}