Problem
In the mysterious country of Byteland, everything is quite different from what you’d normally expect. In most places, if you were approached by two mobsters in a dark alley, they would probably tell you to give them all the money that you have. If you refused, or didn’t have any – they might even beat you up.
In Byteland the government decided that even the slightest chance of someone getting injured has to be ruled out. So, they introduced a strict policy. When a mobster approaches you in a dark alley, he asks you for a specific amount of money. You are obliged to show him all the money that you have, but you only need to pay up if he can find a subset of your banknotes whose total value matches his demand. Since banknotes in Byteland can have any positive integer value smaller than one thousand you are quite likely to get off without paying.
Both the citizens and the gangsters of Byteland have very positive feelings about the system. No one ever gets hurt, the gangsters don’t lose their jobs, and there are quite a few rules that minimize that probability of getting mugged (the first one is: don’t go into dark alleys – and this one is said to work in other places also).
Input
The first line contains integer t, the number of test cases (about 100). Then t test cases follow. Each test case starts with n, the number of banknotes in your wallet, and m, the amount of money the muggers asked of you. Then n numbers follow, representing values of your banknotes. Your wallet does not hold more than 20 banknotes, and the value of a single banknote is never more than 1000.
Output
For each test case output a single line with the word ‘Yes’ if there is a subset of your banknotes that sums to m, and ‘No’ otherwise.
Example
Input: 5 3 3 1 1 1 5 11 1 2 4 8 16 5 23 1 2 4 8 16 5 13 1 5 5 10 10 20 132 17 6 4 998 254 137 259 153 154 3 28 19 123 542 857 23 687 35 99 999 Output: Yes Yes Yes No Yes
Explanation: For example, in the last case you have to pay up, since: 6+3+123=132.
Paying up – CodeChef Solution in JAVA
import java.util.Scanner;
import java.util.stream.IntStream;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int t = sc.nextInt();
for (int tc = 0; tc < t; tc++) {
int n = sc.nextInt();
int m = sc.nextInt();
int[] banknotes = new int[n];
for (int i = 0; i < banknotes.length; i++) {
banknotes[i] = sc.nextInt();
}
System.out.println(solve(banknotes, m) ? "Yes" : "No");
}
sc.close();
}
static boolean solve(int[] banknotes, int m) {
int n = banknotes.length;
for (int code = 0; code < (1 << n); code++) {
boolean used[] = decode(code, n);
if (IntStream.range(0, n).filter(i -> used[i]).map(i -> banknotes[i]).sum() == m) {
return true;
}
}
return false;
}
static boolean[] decode(int code, int size) {
boolean[] result = new boolean[size];
for (int i = 0; i < result.length; i++) {
result[i] = code % 2 == 1;
code >>= 1;
}
return result;
}
}Disclaimer: The above Problem (Paying up) is generated by CodeChef but the solution is provided by Chase2learn. This tutorial is only for Educational and Learning purpose.
