McNuggets problem: Difference between revisions
Content added Content deleted
ReeceGoding (talk | contribs) m (→{{header|R}}: Syntax highlighting.) |
ReeceGoding (talk | contribs) (→{{header|R}}: Mostly syntax improvements.) |
||
| Line 1,677: | Line 1,677: | ||
There are two natural approaches. The first is to generate all valid x, y, and z and then apply the function: |
There are two natural approaches. The first is to generate all valid x, y, and z and then apply the function: |
||
<lang rsplus>allInputs<-expand.grid(x=0:(100%/%6),y=0:(100%/%9),z=0:(100%/%20)) |
<lang rsplus>allInputs <- expand.grid(x = 0:(100 %/% 6), y = 0:(100 %/% 9), z = 0:(100 %/% 20)) |
||
mcNuggets<-do.call(function(x,y,z) 6*x + 9*y + 20*z, allInputs)</lang> |
mcNuggets <- do.call(function(x, y, z) 6 * x + 9 * y + 20 * z, allInputs)</lang> |
||
The second is to find all of the valid 6x, 9y, and 20z, and then sum them: |
The second is to find all of the valid 6x, 9y, and 20z, and then sum them: |
||
<lang rsplus>mcNuggets2<-rowSums(expand.grid(seq(0,100,6),seq(0,100,9),seq(0,100,20)))</lang> |
<lang rsplus>mcNuggets2 <- rowSums(expand.grid(seq(0, 100, 6), seq(0, 100, 9), seq(0, 100, 20)))</lang> |
||
Either way, we get identical results, as checked by: |
Either way, we get identical results, as checked by: |
||
<lang rsplus>all(mcNuggets==mcNuggets2)</lang> |
<lang rsplus>all(mcNuggets == mcNuggets2)</lang> |
||
For our final answer, note that our choice to remove values from the vector 0:100 means our outputs will already be sorted, unique, and no greater than 100. |
For our final answer, note that our choice to remove values from the vector 0:100 means our outputs will already be sorted, unique, and no greater than 100. |
||
<lang rsplus>results<-setdiff(0:100,mcNuggets) |
<lang rsplus>results <- setdiff(0:100, mcNuggets) |
||
cat("The non-McNuggets numbers that are no greater than 100 are:",results,"\nThe largest is",max(results),"\n")</lang> |
cat("The non-McNuggets numbers that are no greater than 100 are:", results, "\nThe largest is", max(results), "\n")</lang> |
||
Ultimately, this can be done in one line: |
Ultimately, this can be done in one line: |
||
<lang rsplus>max(setdiff(0:100,rowSums(expand.grid(seq(0,100,6),seq(0,100,9),seq(0,100,20)))))</lang> |
<lang rsplus>max(setdiff(0:100, rowSums(expand.grid(seq(0, 100, 6), seq(0, 100, 9), seq(0, 100, 20)))))</lang> |
||
However, using seq without naming its arguments is considered bad practice. It works here, but breaking this code up is probably a better idea. |
|||
{{output}} |
{{output}} |
||
<pre>> all(mcNuggets==mcNuggets2) |
<pre>> all(mcNuggets == mcNuggets2) |
||
[1] TRUE</pre> |
[1] TRUE</pre> |
||
<pre>The non-McNuggets numbers that are no greater than 100 are: 1 2 3 4 5 7 8 10 11 13 14 16 17 19 22 23 25 28 31 34 37 43 |
<pre>The non-McNuggets numbers that are no greater than 100 are: 1 2 3 4 5 7 8 10 11 13 14 16 17 19 22 23 25 28 31 34 37 43 |
||
The largest is 43 </pre> |
The largest is 43 </pre> |
||
<pre>> max(setdiff(0:100,rowSums(expand.grid(seq(0,100,6),seq(0,100,9),seq(0,100,20))))) |
<pre>> max(setdiff(0:100, rowSums(expand.grid(seq(0, 100, 6), seq(0, 100, 9), seq(0, 100, 20))))) |
||
[1] 43</pre> |
[1] 43</pre> |
||