题解：http://www.matrix67.com/blog/archives/266
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#include <cstdio>int n,ans,upperlim;void
test(int
row,int
ld,int
rd){ int
pos,p; if
(row!=upperlim) { pos=upperlim&(~(row|ld|rd)); while(pos) { p=pos&(~pos+1); pos=pos-p; test(row|p,(ld|p)<<1,(rd|p)>>1); } } else
ans++;}int
main(){ int
i; while(scanf("%d",&n)&&n) { upperlim=(1<<n)-1; ans=0; test(0,0,0); printf("%d\n",ans); } return
0;} |
原文：http://www.cnblogs.com/forever97/p/3543090.html