51Nod--1285-山峰和分段

#include <iostream> 
#include <cstdio> 
#include <cstdlib> 
#include <cstring> 
using namespace std; 
const int MAXN = 50005; 

int n, num[MAXN], cnt[MAXN];

bool Judge(int cur){
	for(int i=cur; i<=n; i+=cur){
		if(cnt[i] - cnt[i-cur] < 1){
			return false; 
		}
	}
	return true; 
} 

int main(){
	int ans, mot; 
	while(scanf("%d", &n) != EOF){
		for(int i=1; i<=n; ++i){
			scanf("%d", &num[i]); 
		}
		mot = 0; 
		cnt[1] = cnt[0] = 0; 
		for(int i=2; i<n; ++i){
			if(num[i] > num[i-1] && num[i] > num[i+1]){
				mot++; 
				cnt[i] = cnt[i-1] + 1; 
			}else{
				cnt[i] = cnt[i-1]; 
			}
		}
		cnt[n] = cnt[n-1]; 
		ans = 1; 
		if(mot == 0){
		    ans = 0; 
		}
		for(int i=mot; i>=2; --i){
			if( (n%i == 0) && Judge(n/i)){
				ans = i;  
				break; 
			}
		}
		printf("%d\n", ans );
	}
	return 0; 
}