Math Puzzle #1
By Ken Koon Wong in R r simulation math puzzle vector operator
September 3, 2022
2 ? 1 ? 6 ? 6 ? 200 ? 50 = 416.56
Let ? be an operator of +,-,*,/,^ that are replaceable (can be used more than once)
How would you solve this math puzzle?
One could potentially work out the math manually, but how would you solve this math problem using R?
1. Set operators as a vector
operators <- c("+","-","*","/","^")
2. Set for loop + monte carlo simulation to fit the equation
for (i in c(1:1000000)) {
# monte carlo/random sampling of the operator vectors with replacement
new_op <- sample(operators, 5, replace=T)
# parse the numbers and operators into an expression
expression <- parse(text = paste0("2",new_op[1],"1",new_op[2],"6",
new_op[3],"6",new_op[4],"200",
new_op[5],"50"))
# evaluate the expression, apparently you cannot just
# paste operator and expect R to run it like normal
sum <- eval(expression)
# Set condition, if sum is 416.56 then HOT DIGGITY DOG!
if (sum==416.56) {
# print the answer
print(paste0("found it, the combinations are: ",expression))
break
}
}
## [1] "found it, the combinations are: 2^1 * 6^6/200 - 50"
Conclusion/Lesson learnt
- Use
parseandevalfor operators - simulation is awesome !!! Solved this problem in seconds!
- Posted on:
- September 3, 2022
- Length:
- 1 minute read, 189 words