SubarraySum.java

packagearray;

importjava.util.Scanner;

publicclassSubarraySum {

publicstaticintfindSubarraySum(int[] arr, intstart, intend) {
// make prefix sum array
int[] prefix = newint[arr.length];
prefix[0] = arr[0];

for (inti = 1; i < prefix.length; i++) {
prefix[i] = prefix[i - 1] + arr[i];
 }

if (start == end || (start - 1) < 0) {
returnprefix[end];
 }
returnprefix[end] - prefix[start - 1];
 }

publicstaticvoidmain(String[] args) {

int[] arr = { 1, 2, 3, 4, 5 };

Scannersc = newScanner(System.in);

intqueries = sc.nextInt();

for (inttestcase = 0; testcase < queries; testcase++) {
intstart = sc.nextInt();
intend = sc.nextInt();
System.out.println(findSubarraySum(arr, start, end));
 }
sc.close();
 }
}

/* test case- 
4
0 2
1 4
2 4
1 1
*/