21 lines
365 B
Matlab
21 lines
365 B
Matlab
% 由于函数单调，因此可以用二分法求 x/log(9x) = k 的解
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function result = solve_test(k)
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eps = 1e-3;
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l = 1;
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r = k;
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while r - l > eps
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mid = (l+r) / 2;
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if (foo(mid) < foo(r))
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l = mid;
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else
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r = mid;
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end
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end
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result = l;
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end
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function f = foo(x)
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f = x / log(9 * x);
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end
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