#include <bits/stdc++.h>
using namespace std;
//#define FILE_IO
typedef pair<int, int> pii;
pii qry[500005];
int N, Q;
int sol[500005];
char s[500005];
vector<int> stv, queries[500005];
namespace BinaryIndexedTree
{
int aib[500005];
void update(int pos, int val)
{
for(; pos <= N; pos += (pos & (-pos)))
aib[pos] += val;
}
int query(int pos)
{
int ans = 0;
for(; pos > 0; pos -= (pos & (-pos)))
ans += aib[pos];
return ans;
}
int query(int st, int dr) { return query(dr) - query(st - 1); }
}
namespace SegmentTree
{
int sti, dri, pos, val, ans, pfx;
int sum[2000005], mn[2000005];
void remake(int nod)
{
sum[nod] = sum[nod * 2] + sum[nod * 2 + 1];
mn[nod] = min(mn[nod * 2 + 1], mn[nod * 2] + sum[nod * 2 + 1]);
}
void B(int nod, int st, int dr)
{
if(st == dr)
{
sum[nod] = mn[nod] = s[st];
return;
}
int mij = st + (dr - st) / 2;
B(nod * 2, st, mij);
B(nod * 2 + 1, mij + 1, dr);
remake(nod);
}
void U(int nod, int st, int dr)
{
if(st == dr)
{
sum[nod] = mn[nod] = val;
return;
}
int mij = st + (dr - st) / 2;
if(pos <= mij) U(nod * 2, st, mij);
else U(nod * 2 + 1, mij + 1, dr);
remake(nod);
}
void Q(int nod, int st, int dr)
{
if(sti <= st && dr <= dri)
{
ans = min(ans, pfx + mn[nod]);
return;
}
int mij = st + (dr - st) / 2;
if(sti <= mij) Q(nod * 2, st, mij);
if(mij < dri) Q(nod * 2 + 1, mij + 1, dr);
}
void update(int _pos, int _val)
{
pos = _pos, val = _val;
U(1, 1, N);
}
int query(int st, int dr)
{
sti = st, dri = dr;
pfx = 0;
ans = 1 << 30;
Q(1, 1, N);
return ans;
}
void build() { B(1, 1, N); }
}
int main()
{
#ifdef FILE_IO
freopen("1.in", "r", stdin);
freopen("1.out", "w", stdout);
#endif
scanf("%d\n", &N);
scanf("%s", s + 1);
for(int i = 1; i <= N; i++) s[i] = (s[i] == 'C' ? 1 : -1);
scanf("%d", &Q);
for(int q = 1; q <= Q; q++)
{
int st, dr;
scanf("%d%d", &st, &dr);
qry[q] = {st, dr};
queries[dr].push_back(q);
}
SegmentTree::build();
for(int i = 1; i <= N; i++)
{
if(s[i] == -1)
{
stv.push_back(i);
SegmentTree::update(i, 0);
BinaryIndexedTree::update(i, 1);
}
else
{
if(!stv.empty())
{
int x = stv.back(); stv.pop_back();
SegmentTree::update(x, -1);
BinaryIndexedTree::update(x, -1);
}
}
for(auto id: queries[i])
{
int st = qry[id].first, dr = qry[id].second;
sol[id] = SegmentTree::query(st, dr) + BinaryIndexedTree::query(st, dr);
}
}
for(int i = 1; i <= Q; i++)
printf("%d\n", sol[i]);
return 0;
}
Compilation message
election.cpp: In function 'int main()':
election.cpp:115:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d\n", &N);
~~~~~^~~~~~~~~~~~
election.cpp:116:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%s", s + 1);
~~~~~^~~~~~~~~~~~~
election.cpp:119:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &Q);
~~~~~^~~~~~~~~~
election.cpp:123:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &st, &dr);
~~~~~^~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
14 ms |
12280 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
14 ms |
12280 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
14 ms |
12280 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |