2 3 4 7 8 9 10 11 12 13 14 15 n A.length if ( nI) return 1 fori (1-1)/2 to 0 do B[i] = A[i+1] - A[i] fori (1-1)/2+1 to 1-1 do C[i] = A[i-1] + A[i] Sum=0 for in-1 to 0 do for-n-to 0 do SUM SUM + (A[i] + A[i])2 if (sum