Submission #735293

#	Time	Username	Problem	Language	Result	Execution time	Memory
735293		MODDI	Election (BOI18_election)	C++14	100 / 100	1595 ms	27872 KiB

election

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
typedef long long ll;
typedef pair<long long, long long> pll;
typedef pair<int,int> pii;
typedef vector<long long> vl;
typedef vector<int> vi;
int n;
string str;
struct state{
	int ans;
	int tot;
	int pref;
	int suf;
};
state neutral;
state tree[4 * 500100];
state merge(state a, state b){
    if(a.tot==-(1e9))return b;if(b.tot==-(1e9))return a;
    state c;
    c.tot=a.tot+b.tot;
    c.pref=std::max(a.tot+b.pref,a.pref);
    c.suf=std::max(b.tot+a.suf,b.suf);
    c.ans=std::max(std::max(a.ans+b.tot,a.tot+b.ans),a.pref+b.suf);
    return c;
}
void update(int node, int l, int r, state put, int pos){
	if(l == r && l == pos){
		tree[node] = put;
	}
	else{
		int mid = (l + r) / 2;
		if(pos <= mid)	update(node*2, l, mid, put, pos);
		else	update(node*2+1, mid+1, r, put, pos);
		
		tree[node] =merge(tree[node*2], tree[node*2+1]);
	}
}
state query(int node, int l, int r, int L, int R){
	if(r < L || l > R)	return neutral;
	if(L <= l && r <= R)	return tree[node];
	
	int mid = (l + r) / 2;
	return merge(query(node*2, l, mid, L, R), query(node*2+1, mid+1, r, L, R));
}
int main(){
	cin>>n>>str;
	state neg, pos;
	neg.ans = neg.pref = neg.suf = neg.tot = 1;
	pos.ans = pos.pref = pos.suf = 0;
	pos.tot = -1;
	neutral.tot = -1e9;
	for(int i = 0; i < n; i++){
		if(str[i] == 'C')	update(1, 0, n-1, pos, i);
		else update(1, 0, n-1, neg, i);
	}
	int q;
	cin>>q;
	while(q--){
		int l, r;
		cin>>l>>r;
		l--; r--;
		cout<<query(1, 0, n-1, l, r).ans<<endl;
	}
	return 0;
}

Compilation message (stderr)

election.cpp: In function 'state merge(state, state)':
election.cpp:21:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   21 |     if(a.tot==-(1e9))return b;if(b.tot==-(1e9))return a;
      |     ^~
election.cpp:21:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   21 |     if(a.tot==-(1e9))return b;if(b.tot==-(1e9))return a;
      |                               ^~

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