CF 200 div.1 A
2013-10-11 16:45
Rational Resistance
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
Mad scientist Mike is building a time machine in his spare time. To finish the work, he needs a resistor with a certain resistance value.
However, all Mike has is lots of identical resistors with unit resistance R0 = 1. Elements with other resistance can be constructed from these resistors. In this problem, we will consider the following as elements:
-
one resistor;
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an element and one resistor plugged in sequence;
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an element and one resistor plugged in parallel.
With the consecutive connection the resistance of the new element equals R = Re + R0. With the parallel connection the resistance of the new element equals . In this case Re equals the resistance of the element being connected.
Mike needs to assemble an element with a resistance equal to the fraction . Determine the smallest possible number of resistors he needs to make such an element.
Input
The single input line contains two space-separated integers a and b (1 ≤ a, b ≤ 1018). It is guaranteed that the fraction is irreducible. It is guaranteed that a solution always exists.
Output
Print a single number — the answer to the problem.
Please do not use the %lld specifier to read or write 64-bit integers in С++. It is recommended to use the cin, cout streams or the%I64d specifier.
Sample test(s)
input
1 1
output
1
input
3 2
output
3
input
199 200
output
200
Note
In the first sample, one resistor is enough.
In the second sample one can connect the resistors in parallel, take the resulting element and connect it to a third resistor consecutively. Then, we get an element with resistance . We cannot make this element using two resistors.
【题目大意】 给定阻值为1的电阻,要求将单位电阻随意串并联,得到要求的阻值,且用单位电阻数最小
直接带公式 a/b = R1*R2/R1+R2 要求一电阻阻值为1
//By BLADEVIL var a, b, ans :int64; procedure fuck(a,b:int64); begin if (a=0) or (b=0) then exit; ans:=ans+(a div b); a:=a mod b; if (a<>0) and (b<>0) then begin inc(ans,b div a); fuck(a,b mod a); end; end; begin read(a,b); fuck(a,b); writeln(ans); end.