Sir, when I was solving the prefix sum question I did not get why we are adding the prefix sum of (i-1,j-1)th index if we are interested in only the sum from (i,j) to (x,y).
Regards,
Aditya Mehrotra
Why was V added?
@adityamehrotra275 this is because when we subtract (pre[i-1][y] + pre[x][j-1]) from pre[x][y], the portion from (0,0) to (i-1,j-1) gets subtracted twice!
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