One recursive approach to solve HDU 1016, list all permutations, solve N-queens puzzle.

One recursive approach to solve HDU 1016, list all permutations, solve N-queens puzzle.
Reference:the Video of Stanford cs106b Lecture by Julie Zelenski Https://www.youtube.com/watch?v=NdF1QDTRkck

HDU 1016

#include <cstdio>#include <cstring>#include <string>#include <algorithm>const INT Maxn= -; bool IsPrime (int k) {Static std::stringprime={3,5,7, One, -, -, +, at, in, to,Panax Notoginseng};returnPrime.find (k)!=STD::string:: NPOs;} void Printresult (std::stringSTR) {static char strbuf[2*maxn+5], *p; P=strbuf; for(Auto V:str) {p+=sprintf (P,"%d", (int) v); }    *--p=0;Puts (STRBUF);} void Recsolveprimering (std::stringSOFAR, std::string Rest) {if(Rest. Size () = =1) {if(IsPrime (Rest[0]+sofar. Back()) && IsPrime (Rest[0]+sofar.Front())) Printresult (sofar+Rest);return; } for(int i=0;i<Rest. Size (); ++i) {int x=Rest[I]+sofar. Back();if(IsPrime (Rest[I]+sofar. Back()) {recsolveprimering (sofar+Rest[I],Rest. substr (0, i) +Rest. substr (i+1)); }}}void solveprimering (int n) {static std::string Rest{‘\002‘};if(Rest. Back() <=n) for(int i=Rest. Back()+1; i<=n;++i)Rest. push_back (i);Else Rest. Resize (n1); Recsolveprimering ("\001",Rest);} int main () {#ifndef Online_judgeFreopen ("In.txt","R", stdin);#endifint n,k=0; while(SCANF ("%d", &n) = =1) {if(n>0&& N&LT;=MAXN && (n&1)==0) {printf ("Case%d:\n", ++k);            Solveprimering (n);        Putchar (' \ n '); }    }return 0;}

Permutation, from the video of Stanford cs106b lecture by Julie Zelenski

void Recpermute (stringSofar,string Rest) {if(Rest=="") {cout << sofar << Endl; }Else{ for(int i=Rest.length()-1; i>=0;I.) {            stringnext=sofar+Rest[i];stringremaining=Rest. substr (0, i) +Rest. substr (i+1);        Recpermute (next,remaining); }}}void Listpermutations (strings) {Recpermute ("", s);}

8-queens, can be extended to n-queens, limitation, n<=255, (Howevev 255 is a astronomical number for n-queens)
http://blog.csdn.net/qeatzy/article/details/46811451 contains my C + + code of Leetcode N-queens/n-queens II in this appr Oach

voidPrintqueenboard (stringSTR) {Static Charline[Ten]="........";Putchar(' ['); for(intI=0, tmp;i<8; ++i) {tmp=str[i]-' 0 '; line[tmp]=' Q ';printf("\"%s\ "", line); line[tmp]='. ';if(i==7)Putchar("],\n");Else puts(",");}voidRecsolvequeen (stringSofar,stringRest) {if(rest=="") {Printqueenboard (SOFAR); }Else{intFlag,len; for(intI=0; I<rest.length (); ++i) {flag=1; Len=sofar.length (); for(intj=0; j<len;++j) {if(Rest[i]-sofar[j]==len+i-j | | rest[i]-sofar[j]==j-i-len) {flag==0; Break; }            }if(flag) {Recsolvequeen (Sofar+rest[i],rest.substr (0, i) +rest.substr (i+1)); }        }    }}voidEightqueen () {strings="01234567";//or String s{' \001 ', ' \002 ',...};Recsolvequeen ("", s);}

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced. Ps. If in any-to-improment can be achieved, better performance or whatever, it'll be well-appreciated-let me know, thank s in advance.

One recursive approach to solve HDU 1016, list all permutations, solve n-queens puzzle.