Simon has an array a1, a2, ..., an, consisting of n positive integers. Today Simon asked you to find a pair of integers l, r (1 ≤ l ≤ r ≤ n), such that the following conditions hold:
- there is integer j (l ≤ j ≤ r), such that all integers al, al + 1, ..., ar are divisible by aj;
- value r - l takes the maximum value among all pairs for which condition 1 is true;
Help Simon, find the required pair of numbers (l, r). If there are multiple required pairs find all of them.
The first line contains integer n (1 ≤ n ≤ 3·105).
The second line contains n space-separated integers a1, a2, ..., an (1 ≤ ai ≤ 106).
Print two integers in the first line — the number of required pairs and the maximum value of r - l. On the following line print all l values from optimal pairs in increasing order.
54 6 9 3 6
1 32
51 3 5 7 9
1 41
52 3 5 7 11
5 01 2 3 4 5
In the first sample the pair of numbers is right, as numbers 6, 9, 3 are divisible by 3.
In the second sample all numbers are divisible by number 1.
In the third sample all numbers are prime, so conditions 1 and 2 are true only for pairs of numbers (1, 1), (2, 2), (3, 3), (4, 4), (5, 5).
思路:从数组第一个元素开始向两边延伸,如右边延伸到r,下一轮从r+1开始考虑即可。
# include# include # include # include # include # include # define INF 0x3f3f3f3fusing namespace std;const int MAXN = 3e5;int a[MAXN+3]={0};int main(){ vector v; int n, ans; while(~scanf("%d",&n)) { bool flag = false; ans = -INF; for(int i=1; i<=n; ++i) scanf("%d",&a[i]); for(int i=1; i<=n; ++i) { if(a[i]==1) { flag = true; printf("1 %d\n1\n",n-1); break; } int j, k; for(j=i; j-1>0&&a[j-1]%a[i]==0; --j); for(k=i; k+1<=n&&a[k+1]%a[i]==0; ++k); if(k-j > ans) { ans = k-j; v.clear(); } if(k-j == ans) v.push_back(j); i = k; } if(!flag) { printf("%d %d\n",v.size(), ans); for(int i=0; i