[EAZY] - TapeEquilibrium
[EAZY] - TapeEquilibrium
dkf_genius 发表于3年前
[EAZY] - TapeEquilibrium
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 Task description A non-empty zero-indexed array A consisting of N integers is given. Array A represents numbers on a tape. Any integer P, such that 0 < P < N, splits this tape into two non-empty parts: A[0], A[1], ..., A[P − 1] and A[P], A[P + 1], ..., A[N − 1]. The difference between the two parts is the value of: |(A[0] + A[1] + ... + A[P − 1]) − (A[P] + A[P + 1] + ... + A[N − 1])| In other words, it is the absolute difference between the sum of the first part and the sum of the second part. For example, consider array A such that: ``````A[0] = 3 A[1] = 1 A[2] = 2 A[3] = 4 A[4] = 3`````` We can split this tape in four places: P = 1, difference = |3 − 10| = 7  P = 2, difference = |4 − 9| = 5  P = 3, difference = |6 − 7| = 1  P = 4, difference = |10 − 3| = 7  Write a function: class Solution { public int solution(int[] A); } that, given a non-empty zero-indexed array A of N integers, returns the minimal difference that can be achieved. For example, given: ``````A[0] = 3 A[1] = 1 A[2] = 2 A[3] = 4 A[4] = 3`````` the function should return 1, as explained above. Assume that: N is an integer within the range [2..100,000]; each element of array A is an integer within the range [−1,000..1,000]. Complexity: expected worst-case time complexity is O(N); expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments). Elements of input arrays can be modifie
``````class Solution {
public int solution(int[] A) {
// write your code in Java SE 8

if (A == null || A.length < 2 || A.length > 100000) {
return 0;
}

if (A.length == 2) {
return Math.abs(A[0] - A[1]);
}

int leftSum = A[0];
int rightSum = 0;

for (int j=1; j<A.length; j++) {
rightSum += A[j];
}

int minDiff = Math.abs(leftSum - rightSum);

for (int i=1; i<A.length-1; i++) {
leftSum += A[i];
rightSum -= A[i];
int diff = Math.abs(leftSum - rightSum);
if (diff < minDiff) {
minDiff = diff;
}
}

return minDiff;
}
}``````

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