Recreating the Spring Festival Gala Magic Trick Using Go

The Spring Festival Gala featured a comedic magic act by Liu Qian, which can be modeled as a deterministic "Josephus problem". This tutorial recreates the entire trick using the Go programming language, focusing on slice manipulation rather than formal mathematics.

Step 1 – Shuffle: Four cards are represented by an int slice and shuffled with rand.Shuffle . Example output: [6 7 5 2] .

// we use an int slice `pokers` to store the cards
var pokers []int = []int{2, 7, 6, 5}

// 1. shuffle randomly
rand.NewSource(time.Now().UnixNano())
rand.Shuffle(len(pokers), func(i, j int) {
    pokers[i], pokers[j] = pokers[j], pokers[i]
})
fmt.Printf("1. 洗牌后的牌：%v\n", pokers)

Step 2 – Double the deck: The slice is duplicated using append(pokers, pokers...) , yielding [6 7 5 2 6 7 5 2] .

pokers = append(pokers, pokers...)
fmt.Printf("2. 对折后的牌：%v\n", pokers)

Step 3 – Rotate by name length: If the magician’s name has two characters, the first two cards are moved to the bottom.

pokers = append(pokers[2:], pokers[:2]...)
fmt.Printf("3. 名字长度旋转：%v\n", pokers)

Step 4 – Insert top three cards into the middle: The first three cards are taken out and inserted before the last element.

pokers = append(pokers[3:7], pokers[0], pokers[1], pokers[2], pokers[7])
fmt.Printf("4. 插入中间：%v\n", pokers)

Step 5 – Hide the top card: The top card is stored in top and removed from the slice.

top := pokers[0]
pokers = pokers[1:]
fmt.Printf("5. 隐藏的牌：%d, %v\n", top, pokers)

Step 6 – Regional variation: Assuming the magician is from the north, two cards are taken from the top and inserted before the last card.

pokers = append(pokers[2:6], pokers[0], pokers[1], pokers[6])
fmt.Printf("6. 北方操作：%v\n", pokers)

Step 7 – Gender variation: For a male magician, one card is removed from the top.

pokers = pokers[1:]
fmt.Printf("7. 男性操作：%v\n", pokers)

Step 8 – "Witness the miracle" loop: Seven iterations move the top card to the bottom, simulating the chant "见证奇迹的时刻".

for range []string{"见","证","奇","迹","的","时","刻"} {
    pokers = append(pokers[1:], pokers[0])
}
fmt.Printf("8. 见证奇迹的时刻：%v\n", pokers)

Step 9 – Final blessing: Five repetitions (male case) move the top card to the bottom then discard the next top card, leaving a single card.

for range []int{1,2,3,4,5} {
    // 好运留下来
    pokers = append(pokers[1:], pokers[0])
    // 烦恼丢出去
    pokers = pokers[1:]
}
fmt.Printf("9. 最终牌：%v\n", pokers)

The final slice contains only [7] , matching the hidden top card, thus "witnessing the miracle":

fmt.Printf("见证奇迹：%d == %d", top, pokers[0])

The article also points out a common mistake made by the assistant host (mis‑ordering the insertion in step 6) and provides the corrected code.

All source code is available on GitHub for readers to experiment with.