Programming Questions #1:unimodal Palindromic decompositions
Source: POJ (Coursera statement: The exercises completed on POJ will not count against the final results of Coursera. )
Note: Total time limit: 1000ms memory limit: 65536kB
Describe
A sequence of positive integers is palindromic if it reads the same forward and backward. For example:
23 11 15 1 37 37 1 15 11 23
1 1 2 3 4 7 7 10 7 7 4 3 2 1 1
A palindromic sequence is unimodal palindromic if the values does not decrease up to the middle value and then (since the SE Quence is palindromic) does not increase from the middle to the end for example, the first example sequence above are not Uni Modal palindromic While the second example is.
A unimodal palindromic sequence is a unimodal palindromic decomposition of an integer N, if the sum of the integers in the Sequence is N. For example, all of the unimodal palindromic decompositions of the first few integers is given below:
1: (1)
2: (2), (1 1)
3: (3), (1 1 1)
4: (4), (1 2 1), (2 2), (1 1 1 1)
5: (5), (1 3 1), (1 1 1 1 1)
6: (6), (1 4 1), (2 2 2), (1 1 2 1 1), (3 3),
(1 2 2 1), (1 1 1 1 1 1)
7: (7), (1 5 1), (2 3 2), (1 1 3 1 1), (1 1 1 1 1 1 1)
8: (8), (1 6 1), (2 4 2), (1 1 4 1 1), (1 2 2 2 1),
(1 1 1 2 1 1 1), (4 4), (1 3 3 1), (2 2 2 2),
(1 1 2 2 1 1), (1 1 1 1 1 1 1 1)
Write a program, which computes the number of unimodal palindromic decompositions of an integer.
Input
Input consists of a sequence of positive integers, one per line ending with a 0 (zero) indicating the end.
Output
For each input value except the last, the output was a line containing the input value followed by a space and then the number of Unimodal palindromic decompositions of the input value. See the example on the next page.
Sample input
2345678102324131213920
Sample output
2 23 24 45 36 77 58 1110 1723 10424 199131 5010688213 105585259092 331143
Tips
N < 250
1#include <iostream>2#include <algorithm>3 using namespacestd;4 intN;5 Longupnums[251][251];6 7 //calculates the number of combinations with a maximum number less than Max and an n ascending sequence8 LongUpnum (intNintmax) {9 LongCount =0;Ten if(Upnums[n][max]! =-1)returnUpnums[n][max];//if it's stored, return directly One if(max = =1|| N = =0) { AUpnums[n][max] =1; - return 1; - } the if(Max <1) {//Maximum number cannot be less than 1 -Upnums[n][max] =0; - return 0; - } + if(Max > N) {//If the maximum number is greater than and, then convert to Upnum (max, max) -Upnums[n][max] =Upnum (n,n); + returnUpnums[n][n]; A } at for(inti =1; I <= Max; ++i) { -Count + = Upnum (nI, i); - } -Upnums[n][max] =count; - returncount; - } in - //calculates and sets the number of single-peak sequences of n to LongConbinationnum (intN) { + BOOLeven = (N +1) %2;//determine if n is an odd or an even number - LongCount =0; the for(inti =1; I <= N; ++i) { * int Base, Numofi =1; $ if(even) {Panax Notoginseng if((i%2)) { - Base=2;//if n is an even number and I is odd, then the number of intermediate I can only be an even digit theNumofi =2; +}Else{//if n is even, I is an even number, then the number of intermediate I can be an odd number or even several A Base=1; the } + while((i * Numofi) <=N) { -Count + = Upnum ((N (i * Numofi))/2I1); $Numofi + =Base; $ } -}Else { - if((i%2)) { the Base=2;//if n is an odd number, I can only be odd, then the number of intermediate I can only be odd - while((i * Numofi) <=N) {WuyiCount + = Upnum ((N (i * Numofi))/2I1); theNumofi + =Base; - } Wu } - } About } $ returncount; - } - - intMain () A { + for(inti =0; I <251; ++i) { the for(intj =0; J <251; ++j) { -UPNUMS[I][J] =-1; $ } the } theCin>>N; the while(N) { thecout<<n<<" "<<conbinationnum (N) <<Endl; -Cin>>N; in } the return 0; the}
POJ algorithm BASIC programming problem #1:unimodal palindromic decompositions