上海交通大学：《程序设计基础》课程教学讲义（密西根学院）Lecture Notes_20 Looking Ahead

Step 2 Move from Sre to Dst ■→ ■>

Step 3 Move from Aux to Dst

Step 4 Move from Sre to Aux ■

Step 5 Move from Dst to Sre ■ >

Step 6 Move from Dst to Aux >