God, God, and the heavens.Time
limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others)
Total submission (s): 32673 Accepted Submission (s): 13367
problem DescriptionHDU 2006 ' ACM Contest's Awards gala begins!
In order to enliven the atmosphere, organizers held a special, prize-rich lottery, the specific requirements of this activity is:
First, all participants in the party put a note with their name in the lottery box;
Then, after all the notes are added, each person takes a note from the box;
Finally, if the note is written on its own name, then "Congratulations, the jackpot!" ”
You can imagine the atmosphere at that time, after all, the winner of the prize is everyone's dream twins signature photo! However, just as all the comedy attempts to design often end in tragedy, no one has won the lottery in the end!
My God, God, and the heavens, how could this be?
But let's not get excited, now that's the problem, can you calculate the probability of this happening?
Not counting? Do you also want to end with a tragedy?!
InputThe first line of the input data is an integer c, representing the number of test instances, followed by the C row of data, each line containing an integer n (1<n<=20), representing the number of participants in the lottery.
Outputfor each test instance, output the percentage that this occurs, the output of each instance is a row, the result is two decimal places (rounded), and the format is referenced by the sample output.
Sample Input
12
Sample Output
50%
AuthorLCY
SourceRecursive Solution topic exercise (for beginner)
troubleshooting: Wrong sort. Mismatch formula: dp[i]= (i-1) * (Dp[i-1]+dp[i-2])
AC Code:
#include <iostream> #include <cstdlib> #include <cstdio> #include <cmath> #include <cstring > #include <string> #include <cstdlib> #include <iomanip> #include <algorithm> #include < Time.h>typedef Long long ll;using namespace Std;int main () { int i,t,n;double a[20];scanf ("%d", &t); a[1]=0;a[ 2]=1;for (i=3;i<=20;i++) { a[i]= (i-1) * (A[i-1]+a[i-2]); Wrong sort}while (t--) {scanf ("%d", &n); for (i=1;i<=n;i++) {
HDU 2048 god, God, and the heavens (dp+ + combinatorial math)
