Given an array of integers. Count the number of subsets whose difference between pair of subsets is equals to given difference.
Example 1:
int[] a = {1,1,2,3} difference = 1Output: 3
Explanation: Possible choices are- {1, 3} , {1 , 2}
- {1, 3} , {1 , 2} : Since there are duplicates in input.
- {1,1,2} , {3}
Solution:
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import java.util.Arrays;
public class CountOfSubsetsWithGivenDifferencebetweensubsets {
public static void main(String[] args) {
int[] a = {1, 1, 2, 3};
int diff = 1;
System.out.println(countSubsetsWithDiff(a, diff));
}
static int countSubsetsWithDiff(int[] a, int diff) {
int sum = 0;
for (int i : a) {
sum += i;
}
int c = (diff + sum);
if (c % 2 == 1) {
return 0;
}
c = c / 2;
int[][] dp = new int[c + 1][a.length + 1];
for (int i = 0; i < dp.length; i++) {
for (int j = 0; j < dp[0].length; j++) {
if (i == 0) {
dp[i][j] = 1;
continue;
}
if (j == 0) {
continue;
}
if (a[j - 1] <= i) {
dp[i][j] = dp[i - a[j - 1]][j - 1] + dp[i][j - 1];
} else {
dp[i][j] = dp[i][j - 1];
}
}
}
// for(int[] d : dp) {
// System.out.println(Arrays.toString(d));
// }
return dp[c][a.length];
}
}
