// Copyright 2010-2022 Google LLC // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // [START program] // The Stigler diet problem. package com.google.ortools.linearsolver.samples; // [START import] import com.google.ortools.Loader; import com.google.ortools.linearsolver.MPConstraint; import com.google.ortools.linearsolver.MPObjective; import com.google.ortools.linearsolver.MPSolver; import com.google.ortools.linearsolver.MPVariable; import java.util.ArrayList; import java.util.List; // [END import] /** Stigler diet example. */ public final class StiglerDiet { public static void main(String[] args) { Loader.loadNativeLibraries(); // [START data_model] // Nutrient minimums. List nutrients = new ArrayList<>(); nutrients.add(new Object[] {"Calories (kcal)", 3.0}); nutrients.add(new Object[] {"Protein (g)", 70.0}); nutrients.add(new Object[] {"Calcium (g)", 0.8}); nutrients.add(new Object[] {"Iron (mg)", 12.0}); nutrients.add(new Object[] {"Vitamin A (kIU)", 5.0}); nutrients.add(new Object[] {"Vitamin B1 (mg)", 1.8}); nutrients.add(new Object[] {"Vitamin B2 (mg)", 2.7}); nutrients.add(new Object[] {"Niacin (mg)", 18.0}); nutrients.add(new Object[] {"Vitamin C (mg)", 75.0}); List data = new ArrayList<>(); data.add(new Object[] {"Wheat Flour (Enriched)", "10 lb.", 36, new double[] {44.7, 1411, 2, 365, 0, 55.4, 33.3, 441, 0}}); data.add(new Object[] { "Macaroni", "1 lb.", 14.1, new double[] {11.6, 418, 0.7, 54, 0, 3.2, 1.9, 68, 0}}); data.add(new Object[] {"Wheat Cereal (Enriched)", "28 oz.", 24.2, new double[] {11.8, 377, 14.4, 175, 0, 14.4, 8.8, 114, 0}}); data.add(new Object[] { "Corn Flakes", "8 oz.", 7.1, new double[] {11.4, 252, 0.1, 56, 0, 13.5, 2.3, 68, 0}}); data.add(new Object[] { "Corn Meal", "1 lb.", 4.6, new double[] {36.0, 897, 1.7, 99, 30.9, 17.4, 7.9, 106, 0}}); data.add(new Object[] { "Hominy Grits", "24 oz.", 8.5, new double[] {28.6, 680, 0.8, 80, 0, 10.6, 1.6, 110, 0}}); data.add( new Object[] {"Rice", "1 lb.", 7.5, new double[] {21.2, 460, 0.6, 41, 0, 2, 4.8, 60, 0}}); data.add(new Object[] { "Rolled Oats", "1 lb.", 7.1, new double[] {25.3, 907, 5.1, 341, 0, 37.1, 8.9, 64, 0}}); data.add(new Object[] {"White Bread (Enriched)", "1 lb.", 7.9, new double[] {15.0, 488, 2.5, 115, 0, 13.8, 8.5, 126, 0}}); data.add(new Object[] {"Whole Wheat Bread", "1 lb.", 9.1, new double[] {12.2, 484, 2.7, 125, 0, 13.9, 6.4, 160, 0}}); data.add(new Object[] { "Rye Bread", "1 lb.", 9.1, new double[] {12.4, 439, 1.1, 82, 0, 9.9, 3, 66, 0}}); data.add(new Object[] { "Pound Cake", "1 lb.", 24.8, new double[] {8.0, 130, 0.4, 31, 18.9, 2.8, 3, 17, 0}}); data.add(new Object[] { "Soda Crackers", "1 lb.", 15.1, new double[] {12.5, 288, 0.5, 50, 0, 0, 0, 0, 0}}); data.add( new Object[] {"Milk", "1 qt.", 11, new double[] {6.1, 310, 10.5, 18, 16.8, 4, 16, 7, 177}}); data.add(new Object[] {"Evaporated Milk (can)", "14.5 oz.", 6.7, new double[] {8.4, 422, 15.1, 9, 26, 3, 23.5, 11, 60}}); data.add( new Object[] {"Butter", "1 lb.", 30.8, new double[] {10.8, 9, 0.2, 3, 44.2, 0, 0.2, 2, 0}}); data.add(new Object[] { "Oleomargarine", "1 lb.", 16.1, new double[] {20.6, 17, 0.6, 6, 55.8, 0.2, 0, 0, 0}}); data.add(new Object[] { "Eggs", "1 doz.", 32.6, new double[] {2.9, 238, 1.0, 52, 18.6, 2.8, 6.5, 1, 0}}); data.add(new Object[] {"Cheese (Cheddar)", "1 lb.", 24.2, new double[] {7.4, 448, 16.4, 19, 28.1, 0.8, 10.3, 4, 0}}); data.add(new Object[] { "Cream", "1/2 pt.", 14.1, new double[] {3.5, 49, 1.7, 3, 16.9, 0.6, 2.5, 0, 17}}); data.add(new Object[] { "Peanut Butter", "1 lb.", 17.9, new double[] {15.7, 661, 1.0, 48, 0, 9.6, 8.1, 471, 0}}); data.add(new Object[] { "Mayonnaise", "1/2 pt.", 16.7, new double[] {8.6, 18, 0.2, 8, 2.7, 0.4, 0.5, 0, 0}}); data.add(new Object[] {"Crisco", "1 lb.", 20.3, new double[] {20.1, 0, 0, 0, 0, 0, 0, 0, 0}}); data.add(new Object[] {"Lard", "1 lb.", 9.8, new double[] {41.7, 0, 0, 0, 0.2, 0, 0.5, 5, 0}}); data.add(new Object[] { "Sirloin Steak", "1 lb.", 39.6, new double[] {2.9, 166, 0.1, 34, 0.2, 2.1, 2.9, 69, 0}}); data.add(new Object[] { "Round Steak", "1 lb.", 36.4, new double[] {2.2, 214, 0.1, 32, 0.4, 2.5, 2.4, 87, 0}}); data.add( new Object[] {"Rib Roast", "1 lb.", 29.2, new double[] {3.4, 213, 0.1, 33, 0, 0, 2, 0, 0}}); data.add(new Object[] { "Chuck Roast", "1 lb.", 22.6, new double[] {3.6, 309, 0.2, 46, 0.4, 1, 4, 120, 0}}); data.add( new Object[] {"Plate", "1 lb.", 14.6, new double[] {8.5, 404, 0.2, 62, 0, 0.9, 0, 0, 0}}); data.add(new Object[] {"Liver (Beef)", "1 lb.", 26.8, new double[] {2.2, 333, 0.2, 139, 169.2, 6.4, 50.8, 316, 525}}); data.add(new Object[] { "Leg of Lamb", "1 lb.", 27.6, new double[] {3.1, 245, 0.1, 20, 0, 2.8, 3.9, 86, 0}}); data.add(new Object[] { "Lamb Chops (Rib)", "1 lb.", 36.6, new double[] {3.3, 140, 0.1, 15, 0, 1.7, 2.7, 54, 0}}); data.add(new Object[] { "Pork Chops", "1 lb.", 30.7, new double[] {3.5, 196, 0.2, 30, 0, 17.4, 2.7, 60, 0}}); data.add(new Object[] { "Pork Loin Roast", "1 lb.", 24.2, new double[] {4.4, 249, 0.3, 37, 0, 18.2, 3.6, 79, 0}}); data.add(new Object[] { "Bacon", "1 lb.", 25.6, new double[] {10.4, 152, 0.2, 23, 0, 1.8, 1.8, 71, 0}}); data.add(new Object[] { "Ham, smoked", "1 lb.", 27.4, new double[] {6.7, 212, 0.2, 31, 0, 9.9, 3.3, 50, 0}}); data.add(new Object[] { "Salt Pork", "1 lb.", 16, new double[] {18.8, 164, 0.1, 26, 0, 1.4, 1.8, 0, 0}}); data.add(new Object[] {"Roasting Chicken", "1 lb.", 30.3, new double[] {1.8, 184, 0.1, 30, 0.1, 0.9, 1.8, 68, 46}}); data.add(new Object[] { "Veal Cutlets", "1 lb.", 42.3, new double[] {1.7, 156, 0.1, 24, 0, 1.4, 2.4, 57, 0}}); data.add(new Object[] { "Salmon, Pink (can)", "16 oz.", 13, new double[] {5.8, 705, 6.8, 45, 3.5, 1, 4.9, 209, 0}}); data.add(new Object[] { "Apples", "1 lb.", 4.4, new double[] {5.8, 27, 0.5, 36, 7.3, 3.6, 2.7, 5, 544}}); data.add(new Object[] { "Bananas", "1 lb.", 6.1, new double[] {4.9, 60, 0.4, 30, 17.4, 2.5, 3.5, 28, 498}}); data.add( new Object[] {"Lemons", "1 doz.", 26, new double[] {1.0, 21, 0.5, 14, 0, 0.5, 0, 4, 952}}); data.add(new Object[] { "Oranges", "1 doz.", 30.9, new double[] {2.2, 40, 1.1, 18, 11.1, 3.6, 1.3, 10, 1998}}); data.add(new Object[] { "Green Beans", "1 lb.", 7.1, new double[] {2.4, 138, 3.7, 80, 69, 4.3, 5.8, 37, 862}}); data.add(new Object[] { "Cabbage", "1 lb.", 3.7, new double[] {2.6, 125, 4.0, 36, 7.2, 9, 4.5, 26, 5369}}); data.add(new Object[] { "Carrots", "1 bunch", 4.7, new double[] {2.7, 73, 2.8, 43, 188.5, 6.1, 4.3, 89, 608}}); data.add(new Object[] { "Celery", "1 stalk", 7.3, new double[] {0.9, 51, 3.0, 23, 0.9, 1.4, 1.4, 9, 313}}); data.add(new Object[] { "Lettuce", "1 head", 8.2, new double[] {0.4, 27, 1.1, 22, 112.4, 1.8, 3.4, 11, 449}}); data.add(new Object[] { "Onions", "1 lb.", 3.6, new double[] {5.8, 166, 3.8, 59, 16.6, 4.7, 5.9, 21, 1184}}); data.add(new Object[] { "Potatoes", "15 lb.", 34, new double[] {14.3, 336, 1.8, 118, 6.7, 29.4, 7.1, 198, 2522}}); data.add(new Object[] { "Spinach", "1 lb.", 8.1, new double[] {1.1, 106, 0, 138, 918.4, 5.7, 13.8, 33, 2755}}); data.add(new Object[] {"Sweet Potatoes", "1 lb.", 5.1, new double[] {9.6, 138, 2.7, 54, 290.7, 8.4, 5.4, 83, 1912}}); data.add(new Object[] {"Peaches (can)", "No. 2 1/2", 16.8, new double[] {3.7, 20, 0.4, 10, 21.5, 0.5, 1, 31, 196}}); data.add(new Object[] { "Pears (can)", "No. 2 1/2", 20.4, new double[] {3.0, 8, 0.3, 8, 0.8, 0.8, 0.8, 5, 81}}); data.add(new Object[] { "Pineapple (can)", "No. 2 1/2", 21.3, new double[] {2.4, 16, 0.4, 8, 2, 2.8, 0.8, 7, 399}}); data.add(new Object[] {"Asparagus (can)", "No. 2", 27.7, new double[] {0.4, 33, 0.3, 12, 16.3, 1.4, 2.1, 17, 272}}); data.add(new Object[] { "Green Beans (can)", "No. 2", 10, new double[] {1.0, 54, 2, 65, 53.9, 1.6, 4.3, 32, 431}}); data.add(new Object[] {"Pork and Beans (can)", "16 oz.", 7.1, new double[] {7.5, 364, 4, 134, 3.5, 8.3, 7.7, 56, 0}}); data.add(new Object[] { "Corn (can)", "No. 2", 10.4, new double[] {5.2, 136, 0.2, 16, 12, 1.6, 2.7, 42, 218}}); data.add(new Object[] { "Peas (can)", "No. 2", 13.8, new double[] {2.3, 136, 0.6, 45, 34.9, 4.9, 2.5, 37, 370}}); data.add(new Object[] { "Tomatoes (can)", "No. 2", 8.6, new double[] {1.3, 63, 0.7, 38, 53.2, 3.4, 2.5, 36, 1253}}); data.add(new Object[] {"Tomato Soup (can)", "10 1/2 oz.", 7.6, new double[] {1.6, 71, 0.6, 43, 57.9, 3.5, 2.4, 67, 862}}); data.add(new Object[] { "Peaches, Dried", "1 lb.", 15.7, new double[] {8.5, 87, 1.7, 173, 86.8, 1.2, 4.3, 55, 57}}); data.add(new Object[] { "Prunes, Dried", "1 lb.", 9, new double[] {12.8, 99, 2.5, 154, 85.7, 3.9, 4.3, 65, 257}}); data.add(new Object[] {"Raisins, Dried", "15 oz.", 9.4, new double[] {13.5, 104, 2.5, 136, 4.5, 6.3, 1.4, 24, 136}}); data.add(new Object[] { "Peas, Dried", "1 lb.", 7.9, new double[] {20.0, 1367, 4.2, 345, 2.9, 28.7, 18.4, 162, 0}}); data.add(new Object[] {"Lima Beans, Dried", "1 lb.", 8.9, new double[] {17.4, 1055, 3.7, 459, 5.1, 26.9, 38.2, 93, 0}}); data.add(new Object[] {"Navy Beans, Dried", "1 lb.", 5.9, new double[] {26.9, 1691, 11.4, 792, 0, 38.4, 24.6, 217, 0}}); data.add(new Object[] {"Coffee", "1 lb.", 22.4, new double[] {0, 0, 0, 0, 0, 4, 5.1, 50, 0}}); data.add(new Object[] {"Tea", "1/4 lb.", 17.4, new double[] {0, 0, 0, 0, 0, 0, 2.3, 42, 0}}); data.add( new Object[] {"Cocoa", "8 oz.", 8.6, new double[] {8.7, 237, 3, 72, 0, 2, 11.9, 40, 0}}); data.add(new Object[] { "Chocolate", "8 oz.", 16.2, new double[] {8.0, 77, 1.3, 39, 0, 0.9, 3.4, 14, 0}}); data.add(new Object[] {"Sugar", "10 lb.", 51.7, new double[] {34.9, 0, 0, 0, 0, 0, 0, 0, 0}}); data.add(new Object[] { "Corn Syrup", "24 oz.", 13.7, new double[] {14.7, 0, 0.5, 74, 0, 0, 0, 5, 0}}); data.add(new Object[] { "Molasses", "18 oz.", 13.6, new double[] {9.0, 0, 10.3, 244, 0, 1.9, 7.5, 146, 0}}); data.add(new Object[] {"Strawberry Preserves", "1 lb.", 20.5, new double[] {6.4, 11, 0.4, 7, 0.2, 0.2, 0.4, 3, 0}}); // [END data_model] // [START solver] // Create the linear solver with the GLOP backend. MPSolver solver = MPSolver.createSolver("GLOP"); if (solver == null) { System.out.println("Could not create solver GLOP"); return; } // [END solver] // [START variables] double infinity = java.lang.Double.POSITIVE_INFINITY; List foods = new ArrayList<>(); for (int i = 0; i < data.size(); ++i) { foods.add(solver.makeNumVar(0.0, infinity, (String) data.get(i)[0])); } System.out.println("Number of variables = " + solver.numVariables()); // [END variables] // [START constraints] MPConstraint[] constraints = new MPConstraint[nutrients.size()]; for (int i = 0; i < nutrients.size(); ++i) { constraints[i] = solver.makeConstraint( (double) nutrients.get(i)[1], infinity, (String) nutrients.get(i)[0]); for (int j = 0; j < data.size(); ++j) { constraints[i].setCoefficient(foods.get(j), ((double[]) data.get(j)[3])[i]); } // constraints.add(constraint); } System.out.println("Number of constraints = " + solver.numConstraints()); // [END constraints] // [START objective] MPObjective objective = solver.objective(); for (int i = 0; i < data.size(); ++i) { objective.setCoefficient(foods.get(i), 1); } objective.setMinimization(); // [END objective] // [START solve] final MPSolver.ResultStatus resultStatus = solver.solve(); // [END solve] // [START print_solution] // Check that the problem has an optimal solution. if (resultStatus != MPSolver.ResultStatus.OPTIMAL) { System.err.println("The problem does not have an optimal solution!"); if (resultStatus == MPSolver.ResultStatus.FEASIBLE) { System.err.println("A potentially suboptimal solution was found."); } else { System.err.println("The solver could not solve the problem."); return; } } // Display the amounts (in dollars) to purchase of each food. double[] nutrientsResult = new double[nutrients.size()]; System.out.println("\nAnnual Foods:"); for (int i = 0; i < foods.size(); ++i) { if (foods.get(i).solutionValue() > 0.0) { System.out.println((String) data.get(i)[0] + ": $" + 365 * foods.get(i).solutionValue()); for (int j = 0; j < nutrients.size(); ++j) { nutrientsResult[j] += ((double[]) data.get(i)[3])[j] * foods.get(i).solutionValue(); } } } System.out.println("\nOptimal annual price: $" + 365 * objective.value()); System.out.println("\nNutrients per day:"); for (int i = 0; i < nutrients.size(); ++i) { System.out.println( nutrients.get(i)[0] + ": " + nutrientsResult[i] + " (min " + nutrients.get(i)[1] + ")"); } // [END print_solution] // [START advanced] System.out.println("\nAdvanced usage:"); System.out.println("Problem solved in " + solver.wallTime() + " milliseconds"); System.out.println("Problem solved in " + solver.iterations() + " iterations"); // [END advanced] } private StiglerDiet() {} } // [END program]