#include <bits/stdc++.h>
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using namespace std;
template <class T>
using Ve = vector<T>;
#define ALL(v) (v).begin(), (v).end()
#define pii pair<ll, ll>
#define rep(i, a, b) for(ll i = (a); i <= (b); ++i)
#define per(i, a, b) for(ll i = (a); i >= (b); --i)
#define pb push_back
bool Mbe;
ll read() {
ll x = 0, f = 1; char ch = getchar();
while(ch < '0' || ch > '9') {if(ch == '-') f = -1; ch = getchar();}
while(ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
return x * f;
}
void write(ll x) {
if(x < 0) putchar('-'), x = -x;
if(x > 9) write(x / 10);
putchar(x % 10 + '0');
}
const ll N = 2e6 + 9;
ll n, a[N], ans, stk[N], top, pre[N], bin[N];
bool Med;
int main() {
cerr << fabs(&Med - &Mbe) / 1048576.0 << "MB\n";
n = read();
rep(i, 1, n) a[i] = a[i + n] = read();
rep(i, 1, n * 2) {
while(top && a[stk[top]] < a[i]) --top;
pre[i] = stk[top], stk[++top] = i;
}
ll r = 0, cnt = 0;
rep(l, 1, n) {
while(r < l + n - 1) {
++r;
if(pre[r] < l) ++cnt;
bin[pre[r]]++;
}
ans = max(ans, cnt);
--cnt, bin[pre[l]]--;
cnt += bin[l];
}
write(ans), putchar('\n');
cerr << "\n" << clock() * 1.0 / CLOCKS_PER_SEC * 1000 << "ms\n";
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | #include <bits/stdc++.h> using ll = long long; using ld = long double; using ull = unsigned long long; using namespace std; template <class T> using Ve = vector<T>; #define ALL(v) (v).begin(), (v).end() #define pii pair<ll, ll> #define rep(i, a, b) for(ll i = (a); i <= (b); ++i) #define per(i, a, b) for(ll i = (a); i >= (b); --i) #define pb push_back bool Mbe; ll read() { ll x = 0, f = 1; char ch = getchar(); while(ch < '0' || ch > '9') {if(ch == '-') f = -1; ch = getchar();} while(ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar(); return x * f; } void write(ll x) { if(x < 0) putchar('-'), x = -x; if(x > 9) write(x / 10); putchar(x % 10 + '0'); } const ll N = 2e6 + 9; ll n, a[N], ans, stk[N], top, pre[N], bin[N]; bool Med; int main() { cerr << fabs(&Med - &Mbe) / 1048576.0 << "MB\n"; n = read(); rep(i, 1, n) a[i] = a[i + n] = read(); rep(i, 1, n * 2) { while(top && a[stk[top]] < a[i]) --top; pre[i] = stk[top], stk[++top] = i; } ll r = 0, cnt = 0; rep(l, 1, n) { while(r < l + n - 1) { ++r; if(pre[r] < l) ++cnt; bin[pre[r]]++; } ans = max(ans, cnt); --cnt, bin[pre[l]]--; cnt += bin[l]; } write(ans), putchar('\n'); cerr << "\n" << clock() * 1.0 / CLOCKS_PER_SEC * 1000 << "ms\n"; return 0; } |
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