commit f844f5db591e02f11276a648503d6193210ba624
Author: Zastian Pretorius <zastian00@gmail.com>
Date:   Tue Jul 19 22:34:18 2022 +0100

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.lock b/Cargo.lock
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index 0000000..132337a
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "lpr_project"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..f50b5ab
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "lpr_project"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..db6b999
--- /dev/null
+++ b/src/main.rs
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+use std::io::{self, Write};
+use std::vec::Vec;
+struct Coll {
+    restriction: Vec<f64>,
+    sign: String,
+    rhs: f64,
+}
+fn main() {
+    let amount_restrictions = int_input("Enter amount of restrictions: ");
+    let amount_variables = int_input("Enter amount of variables: ");
+    let mut max_z: Vec<f64> = vec![];
+    for z in 0..amount_variables {
+        let input = float_input(&format!("{}x{}:","Enter max value of variable ",z));
+        max_z.push(input);
+    }
+    let all_colls = fill_coll(amount_restrictions, amount_variables);
+    let mut table: Vec<Vec<f64>> = vec![];
+    //fill in max_z with 0 for the rest of the table till size amount_restrictions
+    for _i in 0..amount_restrictions {
+        max_z.push(0.0);
+    }
+    table.push(max_z);
+
+    let mut count = 0;
+    for mut coll in all_colls{
+        for i in 0..amount_restrictions {
+            //push 1 if i = count
+            if i == count {
+                coll.restriction.push(1.0);
+            } else {
+                coll.restriction.push(0.0);
+            }
+        }
+        coll.restriction.push(coll.rhs);
+        count += 1;
+        table.push(coll.restriction);
+    }
+
+    println!("t*");
+    print_table(&table);
+    println!("");
+    println!("ti");
+    let mut table = flip_z(&mut table);
+    print_table(&table);
+    //pivot table until table is optimal
+    // table is optimal when z has no negative values
+    println!("");
+    let mut optimal = false;
+    while !optimal {
+        let pivot_col = find_pivot_col(&table);
+        let ratio = ratio_test(&table, pivot_col);
+        let pivot_row = find_pivot_row(&ratio);
+        table = pivot_table(&mut table, pivot_row, pivot_col);
+        print_table(&table);
+        println!("");
+        if check_optimal(&table){
+            optimal = true;
+        }
+    }
+    //
+    //
+    //println!("{}",find_pivot_col(&table));
+    //let pivot_col = find_pivot_col(&table);
+    //let ratios = ratio_test(&table, pivot_col);
+    //// print all ratios
+    //for ratio in &ratios {
+    //    println!("");
+    //    println!("{}",ratio);
+    //}
+    //let pivot_row = find_pivot_row(&ratios);
+    //let mut table = pivot_table(&mut table, pivot_row, pivot_col);
+    //println!("");
+    //print_table(&table);
+}
+
+fn check_optimal(table: &Vec<Vec<f64>>) -> bool {
+// tebale is optimal when z has no negative values
+    let mut z_index = 0;
+    for i in 0..table[0].len() {
+        if table[0][i] < 0.0 {
+            z_index = i;
+        }
+    }
+    if z_index == 0 {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+
+fn print_table(table: &Vec<Vec<f64>>) {
+    for i in 0..table.len() {
+        for j in 0..table[i].len() {
+            print!("{:.1$}\t", table[i][j],2);
+        }
+        println!("");
+    }
+}
+
+fn pivot_table(table: &mut Vec<Vec<f64>>, pivot_row: usize, pivot_col: usize) -> Vec<Vec<f64>> {
+    // firnd the pivot point
+    let mut new_table = table.clone();
+    let pivot_point = table[pivot_row+1][pivot_col];
+    // divide pivot row by pivot point
+    for i in 0..table[pivot_row+1].len() {
+        new_table[pivot_row+1][i] = table[pivot_row+1][i] / pivot_point;
+    };
+    // current possition-(pivot_row*new_table pivot_point)
+    for i in 0..table.len() {
+        if i != pivot_row+1 {
+            let current_possition = table[i][pivot_col];
+            for j in 0..table[i].len() {
+                new_table[i][j] = table[i][j] - (current_possition * new_table[pivot_row+1][j]);
+            }
+        }
+    }
+    return new_table;
+}
+
+
+fn flip_z(table: &mut Vec<Vec<f64>>) -> Vec<Vec<f64>>{
+    for i in 0..table[0].len(){
+        if table[0][i] > 0.0 {
+            table[0][i] = -table[0][i];
+        }
+    }
+    table[0].push(0.0);
+    return table.to_vec();
+}
+
+fn find_pivot_col(table: &Vec<Vec<f64>>) -> usize {
+    let mut largest = 0.0;
+    let mut largest_index = 0;
+    for i in 0..table[0].len() {
+        if table[0][i] < largest{
+            largest = table[0][i];
+            largest_index = i;
+        }
+    }
+    return largest_index;
+}
+
+fn ratio_test(table: &Vec<Vec<f64>>, test_col: usize) -> Vec<f64> {
+    let mut ratios: Vec<f64> = vec![];
+    for i in 1..table.len() {
+        if table[i][test_col] != 0.0 {
+            ratios.push(table[i][table[i].len() - 1] / table[i][test_col]);
+        } else {
+            ratios.push(std::f64::MAX);
+        }
+    }
+    return ratios;
+}
+
+fn find_pivot_row(ratios: &Vec<f64>) -> usize {
+    //find the index of the smallest ratio
+    let mut smallest = std::f64::MAX;
+    let mut smallest_index = 0;
+    for i in 0..ratios.len() {
+        if ratios[i] < smallest && ratios[i] > 0.0 {
+            smallest = ratios[i];
+            smallest_index = i;
+        }
+    }
+    return smallest_index;
+}
+
+
+fn fill_coll(amount_restrictions: usize, amount_vars: usize) -> Vec<Coll> {
+    let mut colls : Vec<Coll> = vec![];
+    for _restriction in 0..amount_restrictions {
+        let mut restrictions:Vec<f64> = vec![];
+        let mut count = 1;
+        for _var in 0..amount_vars {
+            let input = float_input(&format!("{}x{}:","Enter restriction ",count));
+            restrictions.push(input.clone());
+            count += 1;
+        }
+        let sign_local = string_input("Enter sign: ");
+        let rhs_local = float_input("Enter rhs: ");
+        let coll_local = Coll {
+            restriction: restrictions,
+            sign: sign_local,
+            rhs: rhs_local,
+        };
+        colls.push(coll_local);
+    }
+    colls
+}
+
+
+
+pub fn string_input(prompt: &str) -> String {
+    print!("{}", prompt);
+    let mut input = String::new();
+    let _ = io::stdout().flush();
+    io::stdin()
+        .read_line(&mut input)
+        .expect("Error reading from STDIN");
+    input.trim().to_string()
+}
+
+pub fn int_input(prompt: &str) -> usize {
+    print!("{}", prompt);
+    let mut input = String::new();
+    let _ = io::stdout().flush();
+    io::stdin()
+        .read_line(&mut input)
+        .expect("Error reading from STDIN");
+    //try to parse the input as usize else return max usize
+    match input.trim().parse::<usize>() {
+        Ok(i) => i,
+        Err(_) => {
+            usize::max_value()
+        }
+    }
+}
+
+pub fn float_input(prompt: &str) -> f64 {
+    print!("{}", prompt);
+    let mut input = String::new();
+    let _ = io::stdout().flush();
+    io::stdin()
+        .read_line(&mut input)
+        .expect("Error reading from STDIN");
+    //try to parse the input as f64 else return max f64
+    let output = input.trim().parse::<f64>().unwrap();
+    output
+}