CF1764A Doremy's Paint

Doremy has $ n $ buckets of paint which is represented by an array $ a $ of length $ n $ . Bucket $ i $ contains paint with color $ a_i $ . Let $ c(l,r) $ be the number of distinct elements in the subarray $ [a_l,a_{l+1},\ldots,a_r] $ . Choose $ 2 $ integers $ l $ and $ r $ such that $ l \leq r $ and $ r-l-c(l,r) $ is maximized.

The input consists of multiple test cases. The first line contains a single integer $ t $ ( $ 1\le t\le 10^4 $ ) — the number of test cases. The description of the test cases follows. The first line of each test case contains a single integer $ n $ ( $ 1 \le n \le 10^5 $ ) — the length of the array $ a $ . The second line of each test case contains $ n $ integers $ a_1,a_2,\ldots,a_n $ ( $ 1 \le a_i \le n $ ). It is guaranteed that the sum of $ n $ does not exceed $ 10^5 $ .

For each test case, output $ l $ and $ r $ such that $ l \leq r $ and $ r-l-c(l,r) $ is maximized. If there are multiple solutions, you may output any.

In the first test case, $ a=[1,3,2,2,4] $ . - When $ l=1 $ and $ r=3 $ , $ c(l,r)=3 $ (there are $ 3 $ distinct elements in $ [1,3,2] $ ). - When $ l=2 $ and $ r=4 $ , $ c(l,r)=2 $ (there are $ 2 $ distinct elements in $ [3,2,2] $ ). It can be shown that choosing $ l=2 $ and $ r=4 $ maximizes the value of $ r-l-c(l,r) $ at $ 0 $ . For the second test case, $ a=[1,2,3,4,5] $ . - When $ l=1 $ and $ r=5 $ , $ c(l,r)=5 $ (there are $ 5 $ distinct elements in $ [1,2,3,4,5] $ ). - When $ l=3 $ and $ r=3 $ , $ c(l,r)=1 $ (there is $ 1 $ distinct element in $ [3] $ ). It can be shown that choosing $ l=1 $ and $ r=5 $ maximizes the value of $ r-l-c(l,r) $ at $ -1 $ . Choosing $ l=3 $ and $ r=3 $ is also acceptable.