#include "bits/stdc++.h"
using namespace std;
const int K=19;
int n, q;
// get INDEX of min in [l,r]
struct st{
vector<int> a;
vector<vector<int>> mn, mx, nxt, h;
st(vector<int> a){
this->a=a;
mn.resize(K, vector<int>(n+1));
mx.resize(K, vector<int>(n+1));
nxt.resize(K, vector<int>(n+1));
h.resize(K, vector<int>(n+1));
for(int i=1; i<=n; i++){
mn[0][i]=mx[0][i]=a[i];
}
for(int j=1; j<K; j++){
for(int i=0; i+(1<<j)<=n+1; i++){
mn[j][i]=min(mn[j-1][i], mn[j-1][i+(1<<(j-1))]);
}
}
for(int j=1; j<K; j++){
for(int i=0; i+(1<<j)<=n+1; i++){
mx[j][i]=max(mx[j-1][i], mx[j-1][i+(1<<(j-1))]);
}
}
for(int i=0; i<=n+1; i++){
int j=i;
int _max=a[i];
for(int k=K-1; k>=0; k--){
if(j+(1<<k)<=n+1 && mn[k][j]==a[i]){
_max=max(_max, mx[k][j]);
j+=(1<<k);
}
}
nxt[0][i]=j;
h[0][i]=_max-a[i];
// cout << "nxt " << i <<" " << j << " " << _max << "-" <<a[i] << "\n";
}
for(int k=1; k<K; k++){
for(int i=0; i+(1<<k)<=n+1; i++){
nxt[k][i]=nxt[k-1][nxt[k-1][i]];
h[k][i]=max(h[k-1][i], h[k-1][i+(1<<(k-1))]);
}
}
}
pair<int,int> qry(int l, int r){
int v=1e9;
int i=l;
for(int k=0; k<K; k++){
if((r-l+1)&(1<<k)){
v=min(v, mn[k][i]);
i+=(1<<k);
}
}
// cout << "mn " << l << " " << r << " " << v << "\n";
i=l;
for(int k=K-1; k>=0; k--){
if(i+(1<<k)>r+1) continue;
if(mn[k][i]>v) i+=(1<<k);
}
int ind=l;
int maxh=-1e9;
for(int p=K-1; p>=0; p--){
if(nxt[p][ind] && nxt[p][ind]<=i){
maxh=max(maxh, h[p][ind]);
ind=nxt[p][ind];
}
}
return {i, maxh};
}
};
int main(){
cin.tie(0)->sync_with_stdio(0);
cin >> n;
vector<int> a(n+1), b(n+1);
for(int i=1; i<=n; i++){
char c; cin >> c;
a[i]=(c=='C'?1:-1);
}
for(int i=n; i>=1; i--){
b[i]=a[n+1-i];
}
for(int i=1; i<=n; i++){
a[i]+=a[i-1];
b[i]+=b[i-1];
}
st st1(a), st2(b);
cin >> q;
while(q--){
int l,r;
cin >> l >> r;
pair<int,int> ii=st1.qry(l-1,r);
int i=ii.first, mx=ii.second;
int j=n-st2.qry(n-r, n+1-l).first;
// cout << "ij " << i << " " << j << "\n";
// cout << mx << "-" << (a[r]-a[i]) << "\n";
cout << a[l-1]-a[i]+max(mx-(a[r]-a[i]), a[n-st2.qry(n-r, n-i).first]-a[r]) << '\n';
}
}
// we're just a room full of strangers
Compilation message
election.cpp: In function 'int main()':
election.cpp:104:9: warning: unused variable 'j' [-Wunused-variable]
104 | int j=n-st2.qry(n-r, n+1-l).first;
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
1492 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
1492 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
1492 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
