Hello to all,today I solve problem A. Greg and Array and I have and misunderstanding: I have to submission,one get accepted and another get wrong answer on test 11.

Accepted

Wrong answer

the difference between this both submission is the line below:

for (i=1;i<=n;i++) dp[i]=dp[i]+dp[i-1];

if I change n with m I get Accepted,Can someone explain me why???

I'm very interesting why this happens,because during the contest this mistake can cost me one problem.