I only wants an algorithm or pseudo-code for this.

Write a program called PlusMinus in Java that reads a text file, in.txt, that contains a list of positive integers (duplicate are possible) separated by spaces and/or line breaks. Zero is not included. After reading the integers, the program saves them in a singly linked list in the same order in which they appear in the input file. Then, without changing the linked list, the program prints out Yes if it is possible to place plus or minus signs in front of each positive integer (including the first one) in the list so that the resulting arithmetic expression equals one of the positive integers in the original list. Otherwise, the program must print out No. Assume that in.txt is in the same folder as your java files and that it contains at least one positive integer.

Only one singly linked list should be used. No additional data structures like array, arraylist or another linked list in program.

Example:

If in.txt contains 1, the program must print out Yes. The expression is +1 and it equals the only one positive integer in the list, 1.

If in.txt contains 7 1 5 2, the program must print out Yes. The expression is +7+1-5+2 and it equals 5. There is another solution: +7+1-5-2 equals 1. Since the goal of the program is to find if there is at least one solution, the program must stop and print Yes after it finds the first solution.