34 lines
712 B
C++
34 lines
712 B
C++
#include<stdio.h>
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#include<string.h>
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#include<string>
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#include<iostream>
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#include<map>
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#include<algorithm>
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using namespace std;
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map<string,double>m;
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double s,sum1,sum2;
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string op;
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int n;
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int main()
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{
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m["A"]=4.0,m["A-"]=3.7,m["B+"]=3.3,m["B"]=3.0;
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m["B-"]=2.7,m["C+"]=2.3,m["C"]=2.0,m["C-"]=1.7;
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m["D"]=1.3,m["D-"]=1.0,m["F"]=0;
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while(cin>>n)
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{
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sum1=0,sum2=0;
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for(int i=0;i<n;i++)
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{
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cin>>s>>op;
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if(op=="P"||op=="N")
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continue;
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sum2+=s;
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sum1+=s*m[op];
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}
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if(sum2==0)
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printf("0.00\n");
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else
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printf("%.2lf\n",sum1/sum2);
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}
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}
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