如何分组计数，并在R中某个值处重新开始计数

install.packages("dplyr")

library(dplyr)

df <- df %>% group_by(value)

df <- df %>% mutate(count = row_number())

# 加载dplyr包
library(dplyr)

# 创建示例数据框
df <- data.frame(value = c("A", "A", "A", "B", "B", "A", "A", "C", "C", "C"))

# 按照value列进行分组计数
df <- df %>% group_by(value) %>% mutate(count = row_number())

# 查看结果
df

# A tibble: 10 x 2
# Groups:   value [3]
   value count
   <chr> <int>
 1 A         1
 2 A         2
 3 A         3
 4 B         1
 5 B         2
 6 A         4
 7 A         5
 8 C         1
 9 C         2
10 C         3