Given two equally sized arrays A and B of size N. A is empty and B has some values.
You need to fill A with an element X such that X belongs to B.
The only operations allowed are:
1. Copy B[i] to A[i].
2. Cyclic shift B by 1 to the the right.
You need to minimise the number of operations.
The first line contains a single positive integer N(1 ≤ N ≤ 106), denoting the size of the arrays.
Next line contains N space separated positive integers denoting the elements of the array B(1 ≤ B[i] ≤ 105).
Output a single integer, denoting the minimum number of operations required.
3
1 2 3
5
6
1 1 2 2 3 3
10
In the first test case:
We can have 5 steps as: fill first element, shift, fill second element, shift, fill third element.
Initially, A = [_, _, _], B = [1, 2, 3]
After step 1, A = [1, _, _], B = [1, 2, 3]
After step 2, A = [1, _, _], B = [3, 1, 2]
After step 3, A = [1, 1, _], B = [3, 1, 2]
After step 4, A = [1, 1, _], B = [2, 3, 1]
After step 5, A = [1, 1, 1], B = [2, 3, 1]
求每个数中相邻区间最大的最小的那个数。
1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 #include <algorithm> 5 #include <map> 6 #include <set> 7 #include <queue> 8 #include <stack> 9 #include <vector> 10 #define ll long long int 11 #define inf 0x3f3f3f3f 12 #define N 1000005 13 #define mem(a) memset(a,0,sizeof(a)) 14 using namespace std; 15 int lowbit(int x){ return x&(-x);} 16 int a[N],b[N/10+5][5]; 17 18 int main(){ 19 int n; 20 cin>>n; 21 for(int i = 1; i <= n; i ++){ 22 scanf("%d", &a[i]); 23 if(!b[a[i]][0]) b[a[i]][1] = b[a[i]][2] = b[a[i]][3] = i; 24 else { 25 b[a[i]][2] = b[a[i]][3]; 26 b[a[i]][3] = i; 27 b[a[i]][4] = max(b[a[i]][4], b[a[i]][3] - b[a[i]][2] - 1); 28 } 29 b[a[i]][0] ++; 30 } 31 int ans = inf; 32 for(int i = 1; i <= n; i ++) { 33 b[a[i]][4] = max(b[a[i]][4], n - b[a[i]][3] + b[a[i]][1] - 1); 34 ans = min(ans, b[a[i]][4] + n); 35 } 36 printf("%d ",ans); 37 return 0; 38 }