Submission #171752

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
171752	2019-12-30T09:53:39 Z	dndhk	Election (BOI18_election)	C++14	82 / 100	1134 ms	148360 KB

election

#include <bits/stdc++.h>

#define all(v) (v).begin(), (v).end()
#define sortv(v) sort(all(v))
#define uniqv(v) (v).erase(unique(all(v)), (v).end())
#define pb push_back
#define FI first
#define SE second
#define lb lower_bound
#define ub upper_bound
#define mp make_pair
#define test 1
#define TEST if(test)

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

const int MOD = 1000000007; // 998244353
const int INF = 2e9;
const ll INFLL = 1e18;
const int MAX_N = 500000;
const int MAX_K = 20;

int N, Q;
string str;
int d[MAX_N+1];

struct S{
	int idx, mx, cnt;
};
S nxt[MAX_N+1][MAX_K+1];

struct SEG{
	struct NODE{
		int l, r;
		int mx;
	};
	int SZ;
	vector<NODE> seg;
	void add(){
		seg.pb({-1, -1, -INF});
	}
	void Init(int x){
		SZ = x;
		add();
		init(0, 0, SZ);
	}
	void init(int idx, int s, int e){
		if(s==e)	{
			seg[idx].mx = d[s];
			return;
		}
		seg[idx].l = seg.size(); add();
		seg[idx].r = seg.size(); add();
		init(seg[idx].l, s, (s+e)/2);
		init(seg[idx].r, (s+e)/2+1, e);
		seg[idx].mx = max(seg[seg[idx].l].mx, seg[seg[idx].r].mx);
	}
	int Mx(int x, int y){
		return mx(0, 0, SZ, x, y);
	}
	int mx(int idx, int s, int e, int x, int y){
		if(x<=s && e<=y){
			return seg[idx].mx;
		}
		if(x>e || y<s)	return -INF;
		return max(mx(seg[idx].l, s, (s+e)/2, x, y), mx(seg[idx].r, (s+e)/2+1, e, x, y));
	}
}Seg;

vector<int> st;

int main(){
	scanf("%d", &N);
	cin>>str;
	str.pb('0');
	for(int i=str.size(); i>0; i--){
		str[i] = str[i-1];
	}
	for(int i=1; i<=N; i++){
		d[i] = d[i-1];
		if(str[i]=='C')	d[i]++;
		else	d[i]--;
	}
	for(int i=0; i<MAX_K; i++)	nxt[N+1][i].idx = N+1;
	Seg.Init(N);
	for(int i=N; i>=0; i--){
		while(!st.empty() && d[st.back()]>d[i])	st.pop_back();
		if(st.empty()){
			nxt[i][0].idx = N+1;
			nxt[i][0].mx = nxt[i][0].cnt = 0;
		}else{
			if(d[st.back()]==d[i]){
				nxt[i][0].idx = st.back();
				nxt[i][0].mx = Seg.Mx(i, st.back()) - d[i];
				nxt[i][0].cnt = 0;
				st.pop_back();
			}else{
				nxt[i][0].idx = st.back();
				nxt[i][0].mx = 0;
				nxt[i][0].cnt = 1;
			}
		}
		for(int j=1; j<MAX_K; j++){
			nxt[i][j].idx = nxt[nxt[i][j-1].idx][j-1].idx;
			nxt[i][j].mx = max(nxt[i][j-1].mx, nxt[nxt[i][j-1].idx][j-1].mx);
			nxt[i][j].cnt = nxt[i][j-1].cnt + nxt[nxt[i][j-1].idx][j-1].cnt;
		}
		st.push_back(i);
	}
	scanf("%d", &Q);
	while(Q--){
		int a, b; scanf("%d%d", &a, &b); a--;
		int t = a, dh = 0, ans = 0;
		for(int i=MAX_K-1; i>=0; i--){
			if(nxt[t][i].idx<=b){
				ans+=nxt[t][i].cnt;
				dh = max(dh, nxt[t][i].mx);
				t = nxt[t][i].idx;
			}
		}
		dh = max(dh, Seg.Mx(t, b) - d[t]);
		dh -= (d[b] - d[t]);
		ans += max(0, dh);
		printf("%d\n", ans);
	}

	return 0;
}

Compilation message

election.cpp: In function 'int main()':
election.cpp:78:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
election.cpp:115:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
  ~~~~~^~~~~~~~~~
election.cpp:117:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a, b; scanf("%d%d", &a, &b); a--;
             ~~~~~^~~~~~~~~~~~~~~~

Subtask #1

28.0 / 28.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	1016 KB	Output is correct
2	Correct	5 ms	1016 KB	Output is correct
3	Correct	5 ms	888 KB	Output is correct
4	Correct	5 ms	1016 KB	Output is correct
5	Correct	5 ms	1016 KB	Output is correct

Subtask #2

54.0 / 54.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	1016 KB	Output is correct
2	Correct	5 ms	1016 KB	Output is correct
3	Correct	5 ms	888 KB	Output is correct
4	Correct	5 ms	1016 KB	Output is correct
5	Correct	5 ms	1016 KB	Output is correct
6	Correct	125 ms	21092 KB	Output is correct
7	Correct	110 ms	21108 KB	Output is correct
8	Correct	111 ms	21028 KB	Output is correct
9	Correct	119 ms	21024 KB	Output is correct
10	Correct	146 ms	21172 KB	Output is correct
11	Correct	146 ms	21092 KB	Output is correct
12	Correct	134 ms	21212 KB	Output is correct
13	Correct	142 ms	21256 KB	Output is correct
14	Correct	135 ms	21160 KB	Output is correct
15	Correct	126 ms	21100 KB	Output is correct

Subtask #3

0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	1016 KB	Output is correct
2	Correct	5 ms	1016 KB	Output is correct
3	Correct	5 ms	888 KB	Output is correct
4	Correct	5 ms	1016 KB	Output is correct
5	Correct	5 ms	1016 KB	Output is correct
6	Correct	125 ms	21092 KB	Output is correct
7	Correct	110 ms	21108 KB	Output is correct
8	Correct	111 ms	21028 KB	Output is correct
9	Correct	119 ms	21024 KB	Output is correct
10	Correct	146 ms	21172 KB	Output is correct
11	Correct	146 ms	21092 KB	Output is correct
12	Correct	134 ms	21212 KB	Output is correct
13	Correct	142 ms	21256 KB	Output is correct
14	Correct	135 ms	21160 KB	Output is correct
15	Correct	126 ms	21100 KB	Output is correct
16	Incorrect	1134 ms	148360 KB	Output isn't correct
17	Halted	0 ms	0 KB	-