Count Subsequence Dp

#1

Why i am getting wrong ans…
Only first test case is getting passed…

#2

@Ram_Vilash_Kumar
you are required to take modulo with 1000000007, so that values does not go beyond that.
add these:-
dp[i]=(2*dp[i-1])%mod;
dp[i]=(mod + dp[i]-dp[last[pos]])%mod; // adding mod is done because there may be a chance due to taking modulo dp[i] may become negativee, so just to maintain the value above zero.

#3

@Ram_Vilash_Kumar
After doing these changes, your code will pass.
So if you don’t have further doubt then please mark this doubt as resolved.

#4

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