UVa 694

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694 - The Collatz Sequence[edit]

Summary[edit]

The Collatz Sequence, also known as the 3n+1 sequence or hailstone numbers, is a sequence of numbers that will eventually enter a 4, 2, 1 loop. This problem requires you to count how many steps it takes before reaching 1, or a specified limit.

Explanation[edit]

A "follow the instructions" problem. See also UVa 100

Optimizations[edit]

Gotchas[edit]

Input[edit]

3 100
34 100
75 250
27 2147483647
101 304
101 303
-1 -1

Output[edit]

Case 1: A = 3, limit = 100, number of terms = 8
Case 2: A = 34, limit = 100, number of terms = 14
Case 3: A = 75, limit = 250, number of terms = 3
Case 4: A = 27, limit = 2147483647, number of terms = 112
Case 5: A = 101, limit = 304, number of terms = 26
Case 6: A = 101, limit = 303, number of terms = 1

See Also[edit]