Hdu1041 computer Transformation

The meaning of the question is clear, mainly to find the recursive formula:

Sum [I] = sum [I-1] + 2 * sum [I-2];

Large numbers are required, but this common addition of large numbers is very familiar.

# Include <iostream> # include <algorithm> using namespace STD; int sum [1010] [100], Len [1010]; void Init () {sum [0] [0] = 0; Len [0] = 0; sum [1] [0] = 0; Len [1] = 0; sum [2] [0] = 1; Len [2] = 0; For (INT I = 3; I <= 1000; I ++) {int K, J; k = 0; For (j = 0; j <= Len [I-2]; j ++) {int temp = sum [I-1] [J] + sum [I-2] [J] * 2 + k; k = temp/10000; sum [I] [J] = TEMP % 10000;} while (j <= Len [I-1]) {int temp = sum [I-1] [J] + K; k = temp/10000; sum [I] [J] = TEMP % 10000; j ++;} If (K! = 0) {sum [I] [J] = K; Len [I] = J;} else Len [I] = J-1;} int main () {Init (); int N; while (scanf ("% d", & n) = 1) {int L = Len [N]; printf ("% d ", sum [N] [l]); For (INT I = L-1; I> = 0; I --) printf ("% 04d", sum [N] [I]); printf ("\ n");} return 0 ;}