Submission #571465

#	Time	Username	Problem	Language	Result	Execution time	Memory
571465		BackNoob	Election (BOI18_election)	C++14	100 / 100	1095 ms	64404 KiB

election

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1) 
#define TASK "task"
#define sz(s) (int) (s).size()

using namespace std;
const int mxN = 5e5 + 227;
const int inf = 1e9 + 277;
const int mod = 24211007;
const ll infll = 1e18 + 7;
const int base = 200;
const int LOG = 29;
 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
	if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
	if (a < b) {a = b; return true;} return false;
}

int pre[mxN];

struct IT{
	int n;
	vector<int> tmax, tmin;
	IT(){}
	IT(int _n) {
		n = _n;
		tmax.resize(n * 4 + 7, -inf);
		tmin.resize(n * 4 + 7, inf);
	}

	void update(int v, int tl, int tr, int pos, int val)
	{
		if(tl == tr) {
			tmax[v] = val;
			tmin[v] = val;
		}
		else {
			int tm = (tl + tr) / 2;
			if(pos <= tm) update(v * 2, tl, tm, pos, val);
			else update(v * 2 + 1, tm + 1, tr, pos, val);
			tmax[v] = max(tmax[v * 2], tmax[v * 2 + 1]);
			tmin[v] = min(tmin[v * 2], tmin[v * 2 + 1]);
		}
	}
	int getmax(int v, int tl, int tr, int l, int r)
	{
		if(l > r) return -inf;
		if(tl == l && tr == r) return tmax[v];
		int tm = (tl + tr) / 2;
		int m1 = getmax(v * 2, tl, tm, l, min(r, tm));
		int m2 = getmax(v * 2 + 1, tm + 1, tr, max(l, tm + 1), r);
		return max(m1, m2);
	}
	int getmin(int v, int tl, int tr, int l, int r)
	{
		if(l > r) return inf;
		if(tl == l && tr == r) return tmin[v];
		int tm = (tl + tr) / 2;
		int m1 = getmin(v * 2, tl, tm, l, min(r, tm));
		int m2 = getmin(v * 2 + 1, tm + 1, tr, max(l, tm + 1), r);
		return min(m1, m2);
	}
	void update(int pos, int val)
	{
		update(1, 1, n, pos, val);
	}

	int getmax(int l, int r)
	{
		return getmax(1, 1, n, l, r);
	}
	int getmin(int l, int r)
	{
		return getmin(1, 1, n, l, r);
	}

} seg;

struct node{
	int lef, rig, sum, mx;
};

struct IT1{
	int n;
	vector<node> t;
	IT1(){}
	IT1(int _n) {
		n = _n;
		t.resize(n * 4 + 7, {0, 0, 0, -inf});
	}

	node modify(node a, node b)
	{
		if(a.mx == -inf) return b;
		if(b.mx == -inf) return a;

		node res;
		res.mx = max(a.mx, b.mx);
		res.sum = a.sum + b.sum;

		res.lef = max(a.lef, a.sum + b.lef);
		res.rig = max(b.rig, b.sum + a.rig);

		maximize(res.mx, res.lef);
		maximize(res.mx, res.rig);
		maximize(res.mx, a.rig + b.lef);
		return res;
	}

	void update(int v, int tl, int tr, int pos, int val)
	{
		if(tl == tr) {
			if(val == -1) t[v] = {0, 0, -1, 0};
			else t[v] = {1, 1, 1, 1};
		}
		else {
			int tm = (tl + tr) / 2;
			if(pos <= tm) update(v * 2, tl, tm, pos, val);
			else update(v * 2 + 1, tm + 1, tr, pos, val);
			t[v] = modify(t[v * 2], t[v * 2 + 1]);
		}
	}

	node getans(int v, int tl, int tr, int l, int r)
	{
		if(l > r) return {0, 0, 0, -inf};
		if(tl == l && tr == r) return t[v];
		int tm = (tl + tr) / 2;
		node m1 = getans(v * 2, tl, tm, l, min(r, tm));
		node m2 = getans(v * 2 + 1, tm + 1, tr, max(l, tm + 1), r);
		node res = modify(m1, m2);
		// cout << m1.lef << ' ' << m1.rig << ' ' << m1.sum << ' ' << m1.mx << endl;
		// cout << m2.lef << ' ' << m2.rig << ' ' << m2.sum << ' ' << m2.mx << endl;
		// cout << res.lef << ' ' << res.rig << ' ' << res.sum << ' ' << res.mx << endl;
		return res;
	}
	int getans(int l, int r)
	{
		return getans(1, 1, n, l, r).mx;
	}

	void update(int pos, int val)
	{
		update(1, 1, n, pos, val);
	}
} seg1;

int n;
int q;
int a[mxN];
int maxleng[mxN];
string s;


void solve()
{	
	cin >> n;
	cin >> s;

	for(int i = 1; i <= n; i++) {
		if(s[i - 1] == 'C') a[i] = 1;
		else a[i] = -1;
	}

	for(int i = 1; i <= n; i++) pre[i] = pre[i - 1] + a[i];
	seg = IT(n);
	seg1 = IT1(n);
	for(int i = 1; i <= n; i++) seg.update(i, pre[i]);

	for(int i = 1; i <= n; i++) seg1.update(i, a[i]);
	
	for(int i = 1; i <= n; i++) {
		if(a[i] == -1) maxleng[i] = 0;
		else maxleng[i] = maxleng[i - 1] + a[i];
	}

	cin >> q;
	while(q--) {
		int l, r;
		cin >> l >> r;

		int mn = seg.getmin(l, r) - pre[l - 1];
		int res = 0;
		int last = pre[r] - pre[l - 1];
		// cout << last << ' ';
		if(mn < 0) {
			res += -mn;
			last += -mn;
		}

		// cout << last << ' ' << seg1.getans(l, r) << endl;


		res += max(0, seg1.getans(l, r) - last);
		cout << res << endl;
	}
}
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen(TASK".in" , "r" , stdin);
    //freopen(TASK".out" , "w" , stdout);
		
    int tc = 1;
    // cin >> tc;
    while(tc--) {
    	solve();
    }
    return 0;
}

• Subtask 1: 28 / 28
• Subtask 2: 54 / 54
• Subtask 3: 18 / 18