44 lines
914 B
C++
44 lines
914 B
C++
#include<iostream>
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#include<string.h>
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using namespace std;
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long N,Ans;
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long Hash[300];
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char St[1111111];
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void Solve(void);
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int main()
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{
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while(cin>>N)
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{
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if(!N)
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break ;
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getchar() ;
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Solve() ;
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}
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return 0 ;
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}
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void Solve(void)
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{
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long i=0,j=0,Now,end;
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gets(St);
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memset(Hash,0,sizeof(Hash));
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end=strlen(St);
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for(Ans=0,Now=0;i<end;i++)
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{
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Hash[St[i]]++;
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if(Hash[St[i]]==1)
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{
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Now++;
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while(Now>N)
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{
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Hash[St[j]]--;
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if(Hash[St[j]]==0)
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Now--;
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j++;
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}
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}
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if(i-j+1>Ans)
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Ans=i-j+1;
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}
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cout<<Ans<<endl;
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}
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