21 lines
299 B
C++
21 lines
299 B
C++
#include<iostream>
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#include<string>
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#include<sstream>
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using namespace std;
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int main()
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{
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string j;
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stringstream num;
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int s,b,n;
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while(true)
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{
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cin>>s>>b;
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n=0;
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num.flush();
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for(int i=0;i<b-s+1;i++) num<<s+i;
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num>>j;
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for(int i=0;i<j.size();i++) if(j[i]=='2') n++;
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cout<<n<<endl;
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}
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}
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