斐波那契数列指的是这样一个数列 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233，377，610，987，1597，2584，4181，6765，10946，17711，28657，46368……..
这个数列从第3项开始，每一项都等于前两项之和。
f(x) = f(x-1) + f(x-2)
实现计算的Rust代码如下
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| fn main(){
for i in 1..101 {
println!("f({})=f({}-1)+f({}-2) = {}", i , i, i, ran(i));
}
}
fn ran(mut i: i32) -> i128 {
let mut total: i128 = 0;
let mut t_1: i128 = 1;
let mut t_2: i128 = 1;
while i > 2 {
total = t_1 + t_2;
t_1 = t_2;
t_2 = total;
i -= 1;
}
return total;
}
|
运行结果
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| f(1)=f(1-1)+f(1-2) = 0
f(2)=f(2-1)+f(2-2) = 0
f(3)=f(3-1)+f(3-2) = 2
f(4)=f(4-1)+f(4-2) = 3
f(5)=f(5-1)+f(5-2) = 5
f(6)=f(6-1)+f(6-2) = 8
f(7)=f(7-1)+f(7-2) = 13
f(8)=f(8-1)+f(8-2) = 21
f(9)=f(9-1)+f(9-2) = 34
f(10)=f(10-1)+f(10-2) = 55
...
f(100)=f(100-1)+f(100-2) = 354224848179261915075
|
