1 #include <stdio.h> 2 int AChessBlockRecorder[10]={0}/*下标层数，内容竖行*/,ThisIsMyPlace[10]={0};/*占领*/ 3 int TheTalentOfTheQueen1[25]={0}; //前一个维度代表主对角线特性,相减同 4 int TheTalentOfTheQueen2[25]={0}; 5 int total=0; 6 void output() 7 { 8 total++; 9 printf("solotion:<%d>--- ",total); 10 int q,w; 11 for(q=1;q<9;q++) 12 { 13 for(w=1;w<9;w++) 14 AChessBlockRecorder[q]==w?printf("☆"):printf("★"); 15 printf(" "); 16 } 17 } 18 int search(int n) 19 { 20 int i; 21 for(i=1;i<=8;i++) 22 { 23 if(ThisIsMyPlace[i]==0&&TheTalentOfTheQueen1[i-n+8]==0&&TheTalentOfTheQueen2[i+n]==0) //此竖行尚未被皇后占领 24 { 25 AChessBlockRecorder[n]=i; 26 ThisIsMyPlace[i]=1; 27 TheTalentOfTheQueen1[i-n+8]=1; 28 TheTalentOfTheQueen2[i+n]=1; 29 if(n==8) output(); 30 else search(n+1); 31 TheTalentOfTheQueen1[i-n+8]=0; 32 TheTalentOfTheQueen2[i+n]=0; 33 ThisIsMyPlace[i]=0; 34 } 35 } 36 } 37 int main() 38 { 39 freopen("o.txt","w",stdout); 40 search(1); 41 return 0; 42 }
算是回溯中比较基本的了。
N皇后就是把数字改一改，注释比较多就不做详细解释了
1 #include <stdio.h> 2 #define MAXN 20 3 int AChessBlockRecorder[MAXN+2]={0}/*下标层数，内容竖行*/,ThisIsMyPlace[MAXN+2]={0};/*竖行占领*/ 4 int TheTalentOfTheQueen1[MAXN+20]={0}; //代表主对角线占领,坐标相减数值相同 5 int TheTalentOfTheQueen2[MAXN+20]={0}; //副对角线，相加相同 6 int total=0; 7 void output() 8 { 9 total++; 10 printf("solotion:<%d>--- ",total); 11 int q,w; 12 for(q=1;q<MAXN+1;q++) 13 { 14 for(w=1;w<MAXN+1;w++) 15 AChessBlockRecorder[q]==w?printf("☆"):printf("★"); 16 printf(" "); 17 } 18 } 19 int search(int n) 20 { 21 int i; 22 for(i=1;i<=MAXN;i++) 23 { 24 if(ThisIsMyPlace[i]==0&&TheTalentOfTheQueen1[i-n+MAXN]==0&&TheTalentOfTheQueen2[i+n]==0) //此竖行、对角线尚未被皇后占领 25 { 26 AChessBlockRecorder[n]=i; //记录盘记录位置 27 ThisIsMyPlace[i]=1; 28 TheTalentOfTheQueen1[i-n+MAXN]=1; //i-n可能越位，加上一个数保证不会越位 29 TheTalentOfTheQueen2[i+n]=1; 30 if(n==MAXN) output(); 31 else search(n+1); 32 TheTalentOfTheQueen1[i-n+MAXN]=0; 33 TheTalentOfTheQueen2[i+n]=0; 34 ThisIsMyPlace[i]=0; //以上都是回溯框架 35 } 36 } 37 } 38 int main() 39 { 40 freopen("o.txt","w",stdout); //注意，20比较作死，300000+种解的时候第一层的皇后还没挪位子 41 search(1); 42 return 0; 43 }