Rust语言解面试题1

/* 比较一下

:http://blog.csdn.net/iilovetopview/article/details/43745059

发现还是D语言的快。

*/

use std::time::duration::Duration;

use std::num::Int;

use std::collections::HashMap;

//use std::collections::hash::map;

pub struct Va {

pub  Ac: Vec<usize>,

pub  aa: HashMap<usize, usize>,

}

fn main() {

let r = Duration::span(fnx);

println!(" time :{} milliseconds",r.num_milliseconds());

}

fn fnx()

{

let ( mut pos,mut n ,mut count)=(0,1,0);

while(n >0)

{

let  mut vc =  Va{Ac:vec![],aa: HashMap::new(),};

pos = Fx(n,vc);

if(n == pos)

{

count +=1;

println!("n is: {0},  Fn(n) is:{1} ",n,pos);

if(count >1) {break;}

}

n+=1;

if(n >200000) {break;}//

}

}

fn Fx (n: usize,mut va:Va) -> usize

{

let ( mut  i,mut y,mut l) = (0,0,0);

let mut x = n;

while(x>=1)

{

y=x%10;

va.aa.insert(i,y);

va.Ac.push(y);

x /= 10;

i+=1;

}

let mut m = va.Ac.len() -1;

let (mut result ,mut h) =(0,0);

h =va.aa[m];

if( n%gPow(m) == 0) {return fnA(h,m);}

else  {return  fnA(h,m)+fnB(m-1,va);}

}

fn fnA(h:usize,m:usize) ->usize

{

if(h == 0) {return 0;}

else if(h==1) {if(m == 0) {return 1;} else {return  m*gPow(m-1)+1;}}

else {if(m == 0) {return 1;}  else {return  gPow(m)+h*m*gPow(m-1);}}

}

fn fnB(m:usize,mut va:Va) ->usize

{

..... //代码略

return  sum + fnB(m-1,va);

}

fn gPow(m: usize) ->usize

{

return  10.pow(m);

}