Backpack corrections and updates for file validation

Lab4/backpack.py

@@ -4,18 +4,16 @@ import matplotlib.pyplot as plt
 import sys
 
 def greedy(n, weight, value, capacity ):
-    ratios = [(value[i] / weight[i], weight[i]) for i in range(n)]
-    ratios.sort(reverse=True, key=lambda x: x[0])
+    pairs = list(zip(value, weight))
+    pairs.sort(reverse=True, key=lambda x: x[0] / x[1])
 
-    current_weight = 0
     current_value = 0
-    items_taken = []
+    currentCapacity = capacity
 
-    for ratio, weight in ratios:
-        if current_weight + weight <= capacity and current_value + value[ratios.index((ratio, weight))] <= capacity:
-            current_weight += weight
-            current_value += value[ratios.index((ratio, weight))]
-            items_taken.append(ratios.index((ratio, weight)))
+    for i in range(n):
+        if pairs[i][1] <= currentCapacity:
+            current_value += pairs[i][0]
+            currentCapacity -= pairs[i][1]
 
     return current_value
 
@@ -61,6 +59,7 @@ def benchmark_containers(container_list, capacity):
         greedy_values.append(gr)
         dynamic_values.append(dyn)
 
+        print(f"greedy: {gr}, dynamic: {dyn}, rel_error: {(dyn - gr) / dyn * 100 if dyn != 0 else 0:.2f}%")
         rel_errors.append((dyn - gr) / dyn * 100 if dyn != 0 else 0)
 
     return greedy_times, dynamic_times, rel_errors
@@ -75,7 +74,7 @@ def benchmark_capacity(capacity_list, containers):
     # For each container number or capacity
     for capacity in capacity_list:
         weights = [random.randint(1, 10) for _ in range(containers)]
-        values = [random.randint(1, 20) for _ in range(containers)]
+        values = [random.randint(2, 20) for _ in range(containers)]
 
         # Dynamic
         start = time.time()
@@ -91,8 +90,9 @@ def benchmark_capacity(capacity_list, containers):
         dynamic_times.append(dyn_time)
         greedy_values.append(gr)
         dynamic_values.append(dyn)
+        print(f"greedy: {gr}, dynamic: {dyn}, rel_error: {(dyn - gr) / dyn * 100 if dyn != 0 else 0:.2f}%")
 
-        rel_errors.append(abs((dyn - gr) / dyn) * 100 if dyn != 0 else 0)
+        rel_errors.append((dyn - gr) / dyn * 100 if dyn != 0 else 0)
 
     return greedy_times, dynamic_times, rel_errors
 
@@ -115,20 +115,22 @@ if __name__ == "__main__":
             capacity = int(lines[3].strip())
 
             dynamic(n, weights, values, capacity, print_table=True)
+            print(greedy(n, weights, values, capacity))
         exit(0)
 
     # First test case - constant capacity, variable number of containers
-    containers_list = list(range(5, 101, 5))
+    containers_list = list(range(1, 51, 2))
 
     # Constant capacity of 20
     greedy_times, dynamic_times, rel_errors = benchmark_containers(containers_list, 20)
 
     plt.figure(figsize=(12,5))
     plt.subplot(1,2,1)
-    plt.plot(containers_list, greedy_times, label='Zachłanny', marker='o')
-    plt.plot(containers_list, dynamic_times, label='Dynamiczny', marker='o')
+    plt.plot(containers_list, greedy_times, label='Zachłanny', )
+    plt.plot(containers_list, dynamic_times, label='Dynamiczny', )
     plt.xlabel('Liczba kontenerów')
     plt.ylabel('Czas [ms]')
+    # plt.yscale('log', base=2)
     plt.title('Czas działania dla zmiennej liczby kontenerów (B=20)')
     plt.legend()
 
@@ -149,8 +151,8 @@ if __name__ == "__main__":
 
     plt.figure(figsize=(12,5))
     plt.subplot(1,2,1)
-    plt.plot(capacity_list, greedy_times, label='Zachłanny', marker='o')
-    plt.plot(capacity_list, dynamic_times, label='Dynamiczny' , marker='o')
+    plt.plot(capacity_list, greedy_times, label='Zachłanny' )
+    plt.plot(capacity_list, dynamic_times, label='Dynamiczny')
     plt.xlabel('Pojemność')
     plt.ylabel('Czas [ms]')
     plt.title('Czas działania dla zmiennej pojemności (n=50)')