updated prime paths

rust/insert_digit_anywhere_primes_ev/Cargo.toml

@@ -7,5 +7,5 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-uint = "0.8.3"
+is_prime = "1.0.5"
 rand = "0.7.3"

rust/insert_digit_anywhere_primes_ev/log

@@ -1 +0,0 @@
-0, 7, 17, 137, 1637, 18637, 198637, 1986037, 19986037, 199860337, 1998660337, 19998660337, 199098660337, 1949098660337, 19490986560337, 194909865603317, 1949098656033817, 19490983656033817, 

rust/insert_digit_anywhere_primes_ev/src/main.rs

@@ -1,62 +1,70 @@
-use std::io::prelude::*;
-use uint::construct_uint;
+use is_prime::is_prime_with_witnesses;
 use rand::prelude::*;
+use std::io::prelude::*;
 
-construct_uint! {
-    pub struct U256(4);
-}
-
-fn is_prime(x: &U256) -> bool {
-    let zero = U256::from_dec_str("0").unwrap();
-    let six = U256::from_dec_str("6").unwrap();
-    if x % 2 == zero || x % 3 == zero {
-        return false;
-    }
-    let mut i = U256::from_dec_str("5").unwrap();
-    while i * i < *x {
-        if x % i == zero || x % (i + 2) == zero {
-            return false;
-        }
-        i += six;
-    }
-    true
-}
-
-fn step(x: &U256, rng: &mut ThreadRng) -> Option<U256> {
+fn step(x: String, rng: &mut ThreadRng) -> Option<String> {
     let mut count = 0;
     loop {
-        let mut str_x = format!("{}", x);
         count += 1;
-        if count > 10 * str_x.len() {
+        if count > 10 * x.len() {
             return None;
         }
-        let i = rng.gen_range(0, str_x.len() + 1);
+        let i = rng.gen_range(0, x.len() + 1);
         let d = rng.gen_range(0, 10) as u8;
-        str_x.insert(i, (d + '0' as u8) as char);
-        let temp = U256::from_dec_str(&str_x).unwrap();
-        if !(i == 0 && d == 0) {
-            if is_prime(&temp) {
-                return Some(temp);
+        let mut copy = x.clone();
+        copy.insert(i, (d + '0' as u8) as char);
+        if copy.as_bytes()[0] != '0' as u8 {
+            if is_prime_with_witnesses(&copy, 40) {
+                return Some(copy);
             }
         }
     }
 }
 
 fn main() {
-    let mut x = U256::from_dec_str("0").unwrap();
     let mut rng = thread_rng();
-    let mut length = 0;
+    let mut x;
+    match rng.gen_range(0, 4) {
+        0 => x = String::from("2"),
+        1 => x = String::from("3"),
+        2 => x = String::from("5"),
+        3 => x = String::from("7"),
+        _ => x = String::from("0"),
+    }
+    let mut length = 1;
+    println!("{}", x);
     loop {
-        match step(&x, &mut rng) {
+        match step(x, &mut rng) {
             Some(val) => {
                 length += 1;
-                print!("{}, ", x);
-                std::io::stdout().flush().ok().expect("Could not flush stdout");
+                println!("{}", val);
+                std::io::stdout()
+                    .flush()
+                    .ok()
+                    .expect("Could not flush stdout");
                 x = val;
-            },
+                if length > 100 {
+                    length = 1;
+                    match rng.gen_range(0, 4) {
+                        0 => x = String::from("2"),
+                        1 => x = String::from("3"),
+                        2 => x = String::from("5"),
+                        3 => x = String::from("7"),
+                        _ => x = String::from("0"),
+                    }
+                    println!("{}", x);
+                }
+            }
             None => {
-                x = U256::from_dec_str("0").unwrap();
-                println!(" {}\n\n", length);
+                println!("\n\nUnsucessful! Only length: {}\n\n\n", length);
+                length = 1;
+                match rng.gen_range(0, 4) {
+                    0 => x = String::from("2"),
+                    1 => x = String::from("3"),
+                    2 => x = String::from("5"),
+                    3 => x = String::from("7"),
+                    _ => x = String::from("0"),
+                }
             }
         }
     }