3.Write a program to prefrom knapsack problem using gridy solution. def knapsack(w,wt,val,n): if n-0 or w-0: return 0 if(wt[n-1]>w): return knapsack(w,wt,val,n-1) else: return max(val[n-1]+knapsack(w-wt[n-1],wt,val.n-1),knapsack(w,wt,val,n- 1)) profit [60.100.120] weight-[10.20.30] w=50 n=len(profit) cost-knapsack(w.weight.profit.n) print("the maximun profit by using knapsack problem i:".cost) 1.Selection sort(using user input) def selection_sort(arr): n-len(arr) for i in range(n): min-i for j in range(i+1,n): if arr[j]<arr[min]: min-j arr[i],arr[min]= arr[min],arr[i] n=int(input("enter number of elements:")) arr=[] print("enter".n."elements") for i in range(n): num=int(input(f'enter (i+1}:")) arr.append(num) print("original array is=".arr) selection_sort(arr) print("sorted array is=".arr) 4.write a program to implement DFS graph. #comment:DFS function def dfs(graph,start, visited=None): if visited is None: visi...