35 lines
548 B
C++
35 lines
548 B
C++
//Ñîçäàòåëü Âëàäèñëàâ Óòêèí.
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#include <iostream>
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#include <fstream>
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#include <cmath>
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using namespace std;
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int main() {
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int n;
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double r,pi,a1,b1,per,a2,b2,a,b;
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per=0;
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ifstream d;
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d.open ("input.txt");
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d>>n;
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d>>r;
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d>>a1;
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d>>b1;
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a=a1;
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b=b1;
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while (!d.eof()) {
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d>>a2;
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d>>b2;
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per=per+(sqrt((a2-a1)*(a2-a1)+(b2-b1)*(b2-b1)));
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a1=a2; b1=b2;
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}
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per=per+sqrt((a1-a)*(a1-a)+(b1-b)*(b1-b)+(a2-a1)*(a2-a1)+(b2-b1)*(b2-b1));
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per=per+((2*3.14*r)/4)*n;
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d.close();
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ofstream f;
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f.open ("output.txt");
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f<<per;
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f.close();
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return 0;
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}
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