Contest: https://leetcode.com/contest/weekly-contest-392/
Q1 Longest Strictly Increasing or Strictly Decreasing Subarray
Description: https://leetcode.com/problems/longest-strictly-increasing-or-strictly-decreasing-subarray/description/
Approach: Brute force
Code:
class Solution {
public int longestMonotonicSubarray(int[] nums) {
if (nums.length == 1) return 1;
int inc = 0, dec = 0, countInc = 0, countDec = 0;
int j;
for (int i = 0; i < nums.length-1; i++) {
countInc = 1;
countDec = 1;
for (j=i+1; j<nums.length;j++) if (nums[j] > nums[j-1]) countInc++;else break;
if (countInc > inc) inc = countInc;
for (j=i+1; j<nums.length;j++) if (nums[j] < nums[j-1]) countDec++;else break;
if (countDec > dec) dec = countDec;
}
return Math.max(inc,dec);
}
}
Q2 Lexicographically Smallest String After Operations With Constraint
Description: https://leetcode.com/problems/lexicographically-smallest-string-after-operations-with-constraint/description/
Approach: Greedy.
Code:
class Solution {
public String getSmallestString(String s, int k) {
if (k == 0) return s;
char x ;
int diff;
StringBuilder sb = new StringBuilder();
for (char c : s.toCharArray()) {
if (k==0) {
sb.append(c);
} else {
x = 'a';
diff = Math.min( Math.abs(x-c), (x-c +26) %26);
while (diff > k) {
x++;
diff = Math.min( Math.abs(x-c), (x-c +26) %26);
}
sb.append(x);
k = k - diff;
}
}
return sb.toString();
}
}
Q3 Minimum Operations to Make Median of Array Equal to K
Description: https://leetcode.com/problems/minimum-operations-to-make-median-of-array-equal-to-k/
Code:
class Solution {
public long minOperationsToMakeMedianK(int[] nums, int k) {
Arrays.sort(nums);
int median = nums[nums.length / 2];
long operations = 0;
if (k > median) {
for (int i = nums.length / 2; i < nums.length; i++) {
operations += nums[i] < k ? k - nums[i] : 0;
}
} else {
for (int i = 0; i <= nums.length / 2; i++) {
operations += nums[i] > k ? nums[i] - k : 0;
}
}
return operations;
}
}
Q4 Minimum Cost Walk in Weighted Graph
Description: https://leetcode.com/problems/minimum-cost-walk-in-weighted-graph/description/
Code:
