34 lines
634 B
C++
34 lines
634 B
C++
#include<cstdio>
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typedef long long LL;
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int A,B,Q[40007],cnt,head,tail;
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void dfs(int x,LL y,int p10)
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{
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if(y>B) return;
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if(!x)
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{
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int last=y/(p10/10);
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if(!last) return;
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dfs(x,y+(LL)last*p10,p10*10);
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if(y>=A&&y<=B) ++cnt;
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if(p10<B) Q[tail++]=y;
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return;
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}
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int last=y/(p10/10),nxt=x%10;
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x/=10;
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if(last-nxt>=0) dfs(x,y+p10*(last-nxt),p10*10);
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if(nxt&&last+nxt<10) dfs(x,y+p10*(last+nxt),p10*10);
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}
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int main()
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{
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#ifdef local
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freopen("pro.in","r",stdin);
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#endif
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scanf("%d%d",&A,&B);
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Q[tail++]=7; if(A<=7&&7<=B) ++cnt;
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do
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for(int i=0;i<10;i++) dfs(Q[head],i,10);
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while(++head<tail);
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printf("%d\n",cnt);
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return 0;
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}
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