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Optimal Division – LeetCode Solution Java , Python 3, Python 2 , C , C++, Best and Optimal Solutions , All you need.
You are given an integer array nums. The adjacent integers in nums will perform the float division.
- For example, for
nums = [2,3,4], we will evaluate the expression"2/3/4".
However, you can add any number of parenthesis at any position to change the priority of operations. You want to add these parentheses such the value of the expression after the evaluation is maximum.
Return the corresponding expression that has the maximum value in string format.
Note: your expression should not contain redundant parenthesis.
Example 1:
Input: nums = [1000,100,10,2] Output: "1000/(100/10/2)" Explanation: 1000/(100/10/2) = 1000/((100/10)/2) = 200 However, the bold parenthesis in "1000/((100/10)/2)" are redundant since they do not influence the operation priority. So you should return "1000/(100/10/2)". Other cases: 1000/(100/10)/2 = 50 1000/(100/(10/2)) = 50 1000/100/10/2 = 0.5 1000/100/(10/2) = 2
Example 2:
Input: nums = [2,3,4] Output: "2/(3/4)" Explanation: (2/(3/4)) = 8/3 = 2.667 It can be shown that after trying all possibilities, we cannot get an expression with evaluation greater than 2.667
Constraints:
1 <= nums.length <= 102 <= nums[i] <= 1000- There is only one optimal division for the given input.
C++ Optimal DivisionLeetCode Solution
class Solution {
public:
string optimalDivision(vector<int>& nums) {
int n = nums.size();
string expr;
for (int i = 0; i < n; i++) {
if (i > 0) {
expr += "/";
}
if (i == 1 && n > 2) {
expr += "(";
}
expr += to_string(nums[i]);
if (i == n - 1 && n > 2) {
expr += ")";
}
}
return expr;
}
};
Java Optimal Division LeetCode Solution
public class Solution {
class Result {
String str;
double val;
}
public String optimalDivision(int[] nums) {
int len = nums.length;
return getMax(nums, 0, len - 1).str;
}
private Result getMax(int[] nums, int start, int end) {
Result r = new Result();
r.val = -1.0;
if (start == end) {
r.str = nums[start] + "";
r.val = (double)nums[start];
}
else if (start + 1 == end) {
r.str = nums[start] + "/" + nums[end];
r.val = (double)nums[start] / (double)nums[end];
}
else {
for (int i = start; i < end; i++) {
Result r1 = getMax(nums, start, i);
Result r2 = getMin(nums, i + 1, end);
if (r1.val / r2.val > r.val) {
r.str = r1.str + "/" + (end - i >= 2 ? "(" + r2.str + ")" : r2.str);
r.val = r1.val / r2.val;
}
}
}
//System.out.println("getMax " + start + " " + end + "->" + r.str + ":" + r.val);
return r;
}
private Result getMin(int[] nums, int start, int end) {
Result r = new Result();
r.val = Double.MAX_VALUE;
if (start == end) {
r.str = nums[start] + "";
r.val = (double)nums[start];
}
else if (start + 1 == end) {
r.str = nums[start] + "/" + nums[end];
r.val = (double)nums[start] / (double)nums[end];
}
else {
for (int i = start; i < end; i++) {
Result r1 = getMin(nums, start, i);
Result r2 = getMax(nums, i + 1, end);
if (r1.val / r2.val < r.val) {
r.str = r1.str + "/" + (end - i >= 2 ? "(" + r2.str + ")" : r2.str);
r.val = r1.val / r2.val;
}
}
}
//System.out.println("getMin " + start + " " + end + "->" + r.str + ":" + r.val);
return r;
}
}
Python 3 Optimal Division LeetCode Solution
def optimalDivision(self, A):
A = map(str, A)
if len(A) <= 2: return '/'.join(A)
return '{}/({})'.format(A[0], '/'.join(A[1:]))
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