1.題目如下：
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mmexport1560142169243.jpg
mmexport1560142169243.jpg
2.R解決辦法：
# 定義函數(shù),篩選最終值 ----------------------------------------------------------------------
library(tidyverse)
find_jiou <- function(t){
set.seed(t)
i<-c(1,3,5,7,9)
I <- as.character(i)
j<-c(0,2,4,6,8)
J<- as.character(j)
a<- sample(i,1,replace = T) %>% as.character()
b<- sample(j,1,replace = T)%>% as.character()
c<- sample(j[-1],1,replace = T)%>% as.character()
d<- sample(i,1,replace=T)%>% as.character()
ab <- paste0(a,b,collapse = "") %>% as.numeric()
cd <- paste0(c,d,collapse = "") %>% as.numeric()
r1<- as.character(ab*as.numeric(d)) %>% substring(1:3,1:3)
r2 <-as.character(ab*as.numeric(c)) %>% substring(1:2,1:2)
rf<-as.character(ab*cd) %>% substring(1:3,1:3)
re<- paste0(a,b,c,d,collapse = "") %>% substring(1:4,1:4)
tr1<-(r1 %in% J) %>% all()
tr2<-(r2 %in% J)%>% all()
trf<-(rf %in% J)%>% all()
tlength1 <-r1 %>% paste0(collapse = "") %>% nchar()
tlength1 <-tlength1==3
tlength2 <-r2 %>% paste0(collapse = "") %>% nchar()
tlength2<-tlength2==2
tlengthrf <-rf %>% paste0(collapse = "") %>% nchar()
tlengthrf<-tlengthrf==3
r<-c(tr1,tr2,trf,tlength1,tlength2,tlengthrf)
if(all(r)) print(paste0(re,collapse = "") %>% as.numeric())
}
for (h in 1:625) {
find_jiou(h)
}
#結(jié)果
> for (h in 1:625) {
+ find_jiou(h)
+ }
[1] 3227
[1] 3227
[1] 3227
