#include <algorithm>
#include <bitset>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
using namespace std;
#define PB push_back
#define MP make_pair
#define F first
#define S second
#define ALL(x) (x).begin(),(x).end()
#define SIZE(x) (int)(x).size()
#define CLEAR(tab) memset(tab, 0, sizeof(tab))
#define REP(x, n) for(int x = 0; x < (n); x++)
#define FOR(x, b, e) for(int x = (b); x <= (e); x++)
#define FORD(x, b, e) for(int x = (b); x >= (e); x--)
#define VAR(v, n) __typeof(n) v = (n)
#define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define DEBUG(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__)
typedef long long int LL;
typedef pair<int,int> PII;
typedef vector<int> VI;
const int MXN = 2000010;
const int C = 262144;
const int INF = 1000000001;
const int MOD = 1000000007;
int n;
int a[MXN];
int b[MXN];
int res[MXN];
int s[MXN], ss;
void test() {
scanf("%d", &n);
FOR(i, 1, n) {
scanf("%d", &a[i]);
a[i + n] = a[i];
}
n *= 2;
FOR(i, 1, n) {
while(ss && a[s[ss - 1]] < a[i]) {
b[s[ss - 1]] = i;
ss--;
}
s[ss++] = i;
}
int ans = 0;
FORD(i, n, 1) {
res[i] = res[b[i]] + 1;
ans = max(ans, res[i]);
}
printf("%d\n", ans);
}
int main() {
int te = 1;
//scanf("%d", &te);
while(te--)
test();
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 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | #include <algorithm> #include <bitset> #include <iostream> #include <list> #include <map> #include <queue> #include <set> #include <stack> #include <string> #include <vector> using namespace std; #define PB push_back #define MP make_pair #define F first #define S second #define ALL(x) (x).begin(),(x).end() #define SIZE(x) (int)(x).size() #define CLEAR(tab) memset(tab, 0, sizeof(tab)) #define REP(x, n) for(int x = 0; x < (n); x++) #define FOR(x, b, e) for(int x = (b); x <= (e); x++) #define FORD(x, b, e) for(int x = (b); x >= (e); x--) #define VAR(v, n) __typeof(n) v = (n) #define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i) #define DEBUG(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__) typedef long long int LL; typedef pair<int,int> PII; typedef vector<int> VI; const int MXN = 2000010; const int C = 262144; const int INF = 1000000001; const int MOD = 1000000007; int n; int a[MXN]; int b[MXN]; int res[MXN]; int s[MXN], ss; void test() { scanf("%d", &n); FOR(i, 1, n) { scanf("%d", &a[i]); a[i + n] = a[i]; } n *= 2; FOR(i, 1, n) { while(ss && a[s[ss - 1]] < a[i]) { b[s[ss - 1]] = i; ss--; } s[ss++] = i; } int ans = 0; FORD(i, n, 1) { res[i] = res[b[i]] + 1; ans = max(ans, res[i]); } printf("%d\n", ans); } int main() { int te = 1; //scanf("%d", &te); while(te--) test(); return 0; } |
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