23 lines
400 B
C++
23 lines
400 B
C++
#include <bits/stdc++.h>
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using namespace std;
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const int N = 110;
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double a[N], c[N];
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int main() {
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a[1] = 2;
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c[1] = 1;
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a[2] = 3;
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c[2] = 2;
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double s = a[1] / c[1] + a[2] / c[2];
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for (int i = 3; i <= 20; i++) {
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a[i] = a[i - 1] + a[i - 2];
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c[i] = c[i - 1] + c[i - 2];
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s += a[i] / c[i];
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}
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cout << s << endl;
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return 0;
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} |