Square Brackets--minor help needed

#1

can u point out the mistake in my code.
link —https://ide.codingblocks.com/s/161562

#2

for the first test case:
10
21 6
10 23 14 6 38 7
1 0
18 5
24 13 23 31 15
45 22
73 52 34 20 12 7 37 86 53 4 32 35 48 51 23 79 22 46 79 55 12 35
11 1
4
43 11
58 53 41 38 36 79 35 68 6 50 38
38 20
30 8 3 56 18 58 21 51 12 69 70 66 50 4 1 30 9 60 52 32
14 11
3 22 7 13 26 2 11 18 27 25 10
35 30
58 18 17 60 27 48 64 19 58 39 45 28 2 8 36 40 53 40 42 41 35 60 56 24 13 66 23 30 28 51
40 4
78 63 19 46

Your code is generating 0 for all test cases. So i guess either your answer is getting overflowed. Please check your modulous.
Also i suggest you to use ans = (ans%mod + x%mod)%mod instead of ans+=x; ans%=mod;

#3

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