#include <bits/stdc++.h>
#include "sequence.h"
using namespace std;
const int LIM = 5e5+1;
vector<int> bit(LIM,0);
int n;
void add(int p,int v) {
for (int i=p;i<=n;i+=i&-i) bit[i]+=v;
}
int get(int p) {
int ans = 0;
for (int i=p;i>0;i-=i&-i) ans+=bit[i];
return ans;
}
int sequence(int N, std::vector<int> A) {
n = N;
vector<int> sme(N+1);
vector<int> sm(N+1);
for (int i=1;i<=N;i++) {
add(A[i-1],1);
sme[i] = get(A[i-1]);
sm[i] = get(A[i-1]-1);
}
vector<int> poss[N+1];
for (int i=1;i<=n;i++) poss[A[i-1]].push_back(i);
/*
int l = 1;
int r = N;
while (l<=r) {
int m = (l+r) >> 1;
bool flag = 0;
for (int i=1;i<=n;i++) {
int sz = poss[i].size();
for (int j=0;j+m-1<sz;j++) {
int smme = sme[poss[i][j+m-1]]-sme[poss[i][j]]+1;
int smm = sm[poss[i][j+m-1]]-sm[poss[i][j]];
int len = (poss[i][j+m-1]-poss[i][j]+1);
int mid = (len+1)/2;
if (smme >= mid && smm < mid) flag = 1;
if (len%2==0 && smm<mid+1 && smme>=mid+1) flag = 1;
}
}
if (flag) l = m+1;
else r = m-1;
}*/
int ans = 1;
for (int i=1;i<=n;i++) {
int sz = poss[i].size();
for (int j=0;j<sz;j++) {
for (int j2=j;j2<sz;j2++) {
int smme = sme[poss[i][j2]]-sme[poss[i][j]]+1;
int smm = sm[poss[i][j2]]-sm[poss[i][j]];
int len = (poss[i][j2]-poss[i][j]+1);
int mid = (len+1)/2;
if (smme >= mid && smm < mid) ans = max(ans,j2-j+1);
if (len%2==0 && smm<mid+1 && smme>=mid+1) ans = max(ans,j2-j+1);
}
}
}
return ans;
}
int main() {
int N;
assert(1 == scanf("%d", &N));
std::vector<int> A(N);
for (int i = 0; i < N; ++i) {
assert(1 == scanf("%d", &A[i]));
}
int result = sequence(N, A);
printf("%d\n", result);
return 0;
}
Compilation message
/usr/bin/ld: /tmp/ccI0y3Ur.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccA3CZnp.o:sequence.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
