public int solve(int[] A) {
int oddSum[] = new int[A.length];
int evenSum[] = new int[A.length];
// populate odd and even sums
for (int i = 0; i < A.length; i++) {
if (i % 2 == 1) {
evenSum[i] = A[i];
oddSum[i] = oddSum[i - 1];
}
else {
if (i == 0) {
oddSum[i] = A[i];
}
else {
oddSum[i] = oddSum[i - 1] + A[i];
evenSum[i] = evenSum[i - 1];
}
}
}
int count = 0;
int maxOddSum = oddSum[oddSum.length - 1];
int maxEvenSum = evenSum[evenSum.length - 1];
for (int i = 0; i < A.length; i++) {
if (i % 2 == 1) {
int currentOdd = maxEvenSum - evenSum[i] + oddSum[i];
int currentEven = maxOddSum - oddSum[i] + evenSum[i] - A[i];
if ( currentOdd == currentEven)
count++;
}
else {
int currentEven = maxOddSum - oddSum[i] + evenSum[i];
int currentOdd = maxEvenSum - evenSum[i] + oddSum[i] - A[i];
if ( currentOdd == currentEven)
count++;
}
}
return count;
}
}`Prefix sum based approach
updev
#1