Merge pull request #2 from Starfunk/Update-0.2.0

Update 0.2.0

Cargo.toml

@@ -1,13 +1,13 @@
 [package]
 name = "largeint"
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Maximilian Kahn <[email protected]>"]
 license = "MIT"
-description = "A library that supports large integer arithmetic using LargeInt."
+description = "A library that supports large integer arithmetic."
 readme = "README.md"
 documentation = "https://docs.rs/largeint"
 repository = "https://github.com/Starfunk/largeint"
-keywords = ["largeint", "large", "int","bigint","num"]
-categories = ["no-std"]
+keywords = ["largeint", "int", "large","integer"]
+categories = ["no-std", "data-structures"]
 
 [dependencies]

README.md

@@ -1,11 +1,11 @@
 # largeint
-A library that implements the `LargeInt` type, used for working with arbitrarily large integers in Rust!
+A library that supports large integer arithmetic.
 
 ## Getting Started
 First, add largeint to your dependencies:
 ```toml
 [dependencies]
-largeint = "0.1.0"
+largeint = "0.2.0"
 ```
 Next, add this to the root of your crate to bring the contents of largeint into the scope of your project:
 ```rust
@@ -14,18 +14,24 @@ extern crate largeint;
 use largeint::largeint::*;
 ```
 
-
 You can then easily create many instances of `LargeInt`:
 ```rust
 let largeint1 = new(String::from("999999999999999999999"), Sign::Positive);
 let largeint2 = new(String::from("999999999999999999999"), Sign::Negative);
 let largeint3 = new(String::from("0"), Sign::Unsigned);
 ```
-An instance of `LargeInt` contains two fields, the scalar value of the integer stored as a `String` and the sign of the integer stored as the enum, `Sign`, which can be `Positive`, `Negative`, or `Unsigned` (note that `0` is the only integer that should be assigned `Unsigned`). 
+An instance of `LargeInt` contains two fields, the scalar value of the integer stored as a `String` and the sign of the integer stored as the enum, `Sign`, which can be `Positive`, `Negative`, or `Unsigned` (note that `0` is the only integer that should be assigned `Unsigned`).
+
+Using `new` to create an instance of `LargeInt` is highly recommended as there are checks in place to ensure that the the instance of `LargeInt` will be created properly. For example, creating an instance of a `LargeInt` with a scalar value of `0` using `new` will automatically assign `Sign::Unsigned` to the sign of the LargeInt even if you enter another `Sign` variant.
 
-Using `new()` to create an instance of `LargeInt` is highly recommmended as there are checks in place to ensure that the `LargeInt` will be created properly.
+The purpose of this library is to provide an easy-to-use large integer implementation in Rust.
+The ideal user is one that is looking to write small scale projects for personal use and does
+not want to spend time a lot of time learning a complex crate such as num-bigint. For example,
+this library would be ideal for one looking to solve [Project Euler Problem 13](https://projecteuler.net/problem=13).
+However, the largeint library is not particularly efficient and therefore it is recommended to use
+a crate like num-bigint for more serious projects.
 
-Refer to the documentation for more details.
+Let's see just how easy it is to start performing large integer arithmetic!
 
 ## An Example
 
@@ -46,21 +52,38 @@ fn main() {
     // Subtracting two LargeInts.
     let largeint1 = new(String::from("33901489213409093401849249010492000112"), Sign::Negative);
     let largeint2 = new(String::from("100320394280329423048093284093240234809833999"), Sign::Negative);
-    let largeint3 = largeint1.subtract(&largeint2);
+    let largeint3 = largeint1.sub(&largeint2);
     let largeint4 = new(String::from("100320360378840209638999882243991224317833887"), Sign::Positive);
     assert_eq!(largeint3,largeint4);
-
+
+    // Multiplying two LargeInts.
+    let largeint1 = new(String::from("239014892134090934018492404920112"), Sign::Negative);
+    let largeint2 = new(String::from("820948948039443908494308943885"), Sign::Negative);
+    let largeint3 = largeint1.mul(&largeint2);
+    let largeint4 = new(String::from("196219024263243108752932957733805138559777844813650340515915120"), Sign::Positive);
+    assert_eq!(largeint3,largeint4);
+
+    // Dividing two LargeInts.
+    let largeint1 = new(String::from("33901489213409093401849249010492088384894374938712"), Sign::Positive);
+    let largeint2 = new(String::from("1003203942803294230480932840934343489333999"), Sign::Negative);
+    let largeint3 = largeint1.div(&largeint2);
+    let largeint4 = new(String::from("33793217"), Sign::Negative);
+    assert_eq!(largeint3,largeint4);
+
     //The get_int() method returns the scalar value of the LargeInt as a String.
     println!("The value of largeint1 is: {}", largeint1.get_int());
-    
+
     //The get_sign() method returns the Sign of the LargeInt as a String.
-     println!("The Sign of largeint1 is: {}", largeint1.get_sign());
+    println!("The Sign of largeint1 is: {}", largeint1.get_sign());
 }
 
 ```
+## Updates
+Code Breaking Changes:
+The subtraction method has been renamed `sub` from  `subtraction`.
+
+New Library Additions:
+Multiplication, floor division - and remainder - have been added.  
 
 ## License
 This project is licensed under the MIT License - see [LICENSE.md](https://github.com/Starfunk/largeint/blob/master/LICENSE) for more details.
-
-## Future Updates
-Integer multiplication and division for `LargeInt` is currently being developed and should be released sometime in the next few weeks in the `"0.2.0"` update.

src/addition.rs

@@ -9,7 +9,7 @@ pub fn addition(large1: &str, large2: &str) -> String {
     let mut sum = vec![];
     let mut counter: u8 = 0;
     let mut input: u8;
-    
+
     if large1.len() >= large2.len() {
         large3 = &large1;
         large4 = &large2;
@@ -52,3 +52,53 @@ pub fn addition(large1: &str, large2: &str) -> String {
     let digits = vec_to_str(&sum);
     digits
 }
+
+
+pub fn addition_2(large1: Vec<u8>, large2: Vec<u8>) -> Vec<u8> {
+    let large3: &Vec<u8>;
+    let large4: &Vec<u8>;
+    let mut sum = vec![];
+    let mut counter: u8 = 0;
+    let mut input: u8;
+
+    if large1.len() >= large2.len() {
+        large3 = &large1;
+        large4 = &large2;
+    } else {
+        large3 = &large2;
+        large4 = &large1;
+    }
+    let len_1 = large3.len();
+    let len_2 = large4.len();
+        for i in 0..len_2 {
+            input = large3[len_1 - i - 1] + large4[len_2 - i - 1] + counter;
+            if input >= 10 {
+                input = input - 10;
+                sum.insert(0, input);
+                counter = 1;
+            } else {
+                sum.insert(0, input);
+                counter = 0;
+            }
+        }
+        if len_1 > len_2 {
+            for i in (0..len_1 - len_2).rev() {
+                input = large3[i] + counter;
+
+                if input == 10 {
+                    sum.insert(0, 0);
+                    counter = 1;
+                } else {
+                    sum.insert(0, input);
+                    counter = 0;
+                }
+            }
+            if counter == 1 {
+                sum.insert(0, 1)
+            }
+        }
+        if len_1 == len_2 && counter == 1 {
+            sum.insert(0, 1);
+        }
+    sum
+}

src/division.rs

@@ -0,0 +1,155 @@
+use largeint::*;
+use multiplication::multiplication_1;
+
+pub fn division(large1: &str, large2: &str) -> Vec<String> {
+    let mut divided = String::from("");
+    let mut remainder_largeint: LargeInt;
+    let mut remainder_str = String::from("");
+    let output_vec: Vec<String>;
+    let sign = Sign::Positive;
+    let large2 = new(String::from(large2), sign);
+    let large1_length = large1.len();
+    let mut large1_slice: &str;
+    let mut flag = true;
+    let mut counter = 0;
+    while flag == true {
+        for i in 1..large1_length + 1 {
+            large1_slice = &large1[0..i];
+            let large1_piece = new(String::from(large1_slice), sign);
+            if large1_piece.compare(&large2) == Compare::Smaller {
+                counter += 1;
+                continue
+            } else if large1_piece.compare(&large2) == Compare::Larger {
+                for i in 1..10 {
+                    let index = i.to_string();
+                    let index_str= to_vec(&index[..]);
+                    let large2_vec = to_vec(&large2.digits);
+                    let product = multiplication_1(&large2_vec, &index_str);
+                    let product_vec = vec_to_str(&product);
+                    let product_largeint = new(product_vec, sign);
+                    if large1_piece.compare(&product_largeint) == Compare::Smaller {
+                        let index1 = i - 1;
+                        let index1_str = index1.to_string();
+                        divided.push_str(&index1.to_string());
+                        let index1_largeint = to_vec(&index1_str);
+                        let product_2 = multiplication_1(&large2_vec, &index1_largeint);
+                        let product_vec_2 = vec_to_str(&product_2);
+                        let product_largeint_2 = new(product_vec_2, sign);
+                        remainder_largeint = large1_piece.sub(&product_largeint_2);
+                        remainder_str = remainder_largeint.digits;
+                        flag = false;
+                        break
+                    } else if large1_piece.compare(&product_largeint) == Compare::Equal {
+                        remainder_str = String::from("0");
+                        divided.push_str(&index);
+                        flag = false;
+                        break
+                    }
+                }
+                counter += 1;
+            } else if large1_piece.compare(&large2) == Compare::Equal {
+                remainder_str.push_str("0");
+                divided.push_str("1");
+                counter += 1;
+                flag = false;
+            }
+            break
+        }
+    }
+    if counter != large1_length {
+        for _ in counter..large1_length + 1 {
+            if counter == large1_length {
+                break
+            }
+            if remainder_str == String::from("0") && &large1[counter..counter+1] == "0" {
+                remainder_str = String::from("0");
+                divided.push_str("0");
+                counter += 1;
+            }
+            else if remainder_str == String::from("0") && &large1[counter..counter+1] != "0" {
+                remainder_str = large1[counter..counter+1].to_string();
+                let remainder_largeint = new(remainder_str.clone(), sign);
+                if remainder_largeint.compare(&large2) == Compare::Smaller {
+                    divided.push_str("0");
+                } else if remainder_largeint.compare(&large2) == Compare::Larger {
+                    let output_tuple = find_the_highest_divider(&remainder_str, &large2, &mut divided);
+                    divided = output_tuple.0;
+                    remainder_str = output_tuple.1;
+                } else {
+                    remainder_str = String::from("0");
+                    divided.push_str("0");
+                }
+                counter += 1;
+            } else {
+                remainder_str.push_str(&large1[counter..counter+1]);
+                let mut remainder_largeint = new(remainder_str.clone(), sign);
+                if remainder_largeint.compare(&large2) == Compare::Smaller {
+                    divided.push_str("0");
+                } else if remainder_largeint.compare(&large2) == Compare::Larger {
+                    let output_tuple = find_the_highest_divider(&remainder_str, &large2, &mut divided);
+                    divided = output_tuple.0;
+                    remainder_str = output_tuple.1;
+                } else {
+                    remainder_str = String::from("0");
+                    divided.push_str("1");
+                }
+                counter += 1;
+            }
+        }
+    }
+    output_vec = vec![divided, remainder_str];
+    output_vec
+}
+
+fn find_the_highest_divider(remainder: &String, large2: &LargeInt, divided: &mut String) -> (String, String) {
+    let mut remainder_str = String::from("0");
+    let sign = Sign::Positive;
+    let remainder_largeint = new(remainder.clone(), sign);
+    let large2_vec = to_vec(&large2.digits);
+    let remainder2_largeint: LargeInt;
+    let mut index: String;
+    let mut index_vec: Vec<u8>;
+    let mut product: Vec<u8>;
+    for i in 0..10 {
+        index = i.to_string();
+        index_vec = to_vec(&index[..]);
+        if i == 0 {
+            product = vec![0]
+        } else {
+            product = multiplication_1(&large2_vec, &index_vec);
+        }
+        let product_str = vec_to_str(&product);
+        let product_largeint = new(product_str, sign);
+        if remainder_largeint.compare(&product_largeint) == Compare::Smaller {
+            let index1 = i - 1;
+            let index1_vec: Vec<u8>;
+            let index1_str: String;
+            if index1 == 0 {
+                index1_str = String::from("0");
+            } else {
+                index1_str = index1.to_string();
+            }
+            index1_vec = to_vec(&index1_str[..]);
+            let product1 = multiplication_1(&large2_vec, &index1_vec);
+            let product1_str = vec_to_str(&product1 );
+            let product1_largeint = new(product1_str, sign);
+            divided.push_str(&index1.to_string());
+            remainder2_largeint = remainder_largeint.sub(&product1_largeint);
+            remainder_str = remainder2_largeint.digits;
+            break
+        } else if i == 9 {
+            divided.push_str(&index.to_string());
+            remainder2_largeint = remainder_largeint.sub(&product_largeint);
+            remainder_str = remainder2_largeint.digits;
+            break
+        }
+        else if remainder_largeint.compare(&product_largeint) == Compare::Equal {
+            divided.push_str(&index);
+            remainder_str = String::from("0");
+            break
+        } else {
+            remainder_str = String::from("0");
+        }
+    }
+    (divided.clone(), remainder_str)
+}