| // Copyright 2022 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package util |
| |
| // FindRepeatingPeriod tries to find a repeating pattern in value. |
| // For example, for []uint64{1, 2, 3, 1, 2, 3, 1} it returns 3, true. |
| // It searches greedily and will not always succeed in finding a pattern. |
| func FindRepeatingPeriod(value []uint64) (int, bool) { |
| if len(value) == 0 { |
| return 0, false |
| } |
| |
| period := -1 |
| for i, v := range value[1:] { |
| if v == value[0] { |
| period = i + 1 |
| break |
| } |
| } |
| if period == -1 { |
| return 0, false |
| } |
| |
| for i, v := range value { |
| if v != value[i%period] { |
| return 0, false |
| } |
| } |
| return period, true |
| } |
