River Crossing Puzzle

過河謎題

The Family | 家庭成員

A family needs to cross a river. The family consists of: 一個家庭需要過河。這個家庭包括：

• Father | 爸爸
• Mother | 媽媽
• 2 Sons | 兩個兒子
• 2 Daughters | 兩個女兒
• 1 Servant | 一個僕人
• 1 Dog | 一條狗

Available Resources | 可用資源

• One boat that can carry maximum 2 people/animals at a time 一艘船，一次最多可載兩個人/動物
• Only the father, mother, and servant know how to operate the boat 只有爸爸、媽媽和僕人會開船
• The boat operator counts as one of the two passengers 開船的人算作兩個乘客之一

Constraints | 限制條件

1. When mother is absent and father is present: 當媽媽不在而爸爸在場時：
   • Father will hit the daughters 爸爸會打女兒
   • Mission fails if this occurs 如果發生這種情況，任務失敗
2. When father is absent and mother is present: 當爸爸不在而媽媽在場時：
   • Mother will hit the sons 媽媽會打兒子
   • Mission fails if this occurs 如果發生這種情況，任務失敗
3. When servant is absent: 當僕人不在時：
   • Dog will bite all family members 狗會咬所有家庭成員
   • Mission fails if this occurs 如果發生這種情況，任務失敗

Goal | 目標

Transport the entire family (including the servant and dog) safely across the river in the minimum number of boat crossings while respecting all constraints. 在遵守所有限制條件的情況下，用最少的船程將全家人（包括僕人和狗）安全送到河對岸。

Success Criteria | 成功標準

• All family members must reach the destination side 所有家庭成員必須到達目的地岸
• No violations of the constraints can occur at any point 任何時候都不能違反限制條件
• The number of crossings should be minimized 船程數量應該最少化

Initial State | 初始狀態

Starting side | 起始岸： Father, Mother, 2 Sons, 2 Daughters, Servant, Dog 爸爸、媽媽、兩個兒子、兩個女兒、僕人、狗

Destination side | 目的地岸： Empty | 空

Boat location | 船的位置： At starting side | 在起始岸