39 lines
1.2 KiB
Java
39 lines
1.2 KiB
Java
// Author: Rodney Shaghoulian
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// Github: github.com/RodneyShag
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// HackerRank: hackerrank.com/RodneyShag
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import java.util.Scanner;
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// Idea: Keep track of your "level", which is how far above or below sea level you are.
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// If you ever take a step up to sea level, you just completed walking through a valley.
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// Time Complexity: O(n)
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public class Solution {
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public static void main(String[] args) {
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/* Save input */
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Scanner scan = new Scanner(System.in);
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scan.nextLine(); // gets rid of 1st line
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String str = scan.nextLine(); // String is of size "n"
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scan.close();
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System.out.println(countValleys(str));
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}
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private static int countValleys(String str) {
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int level = 0;
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int numValleys = 0;
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for (int i = 0; i < str.length(); i++) {
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char ch = str.charAt(i);
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if (ch == 'U') {
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level++;
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if (level == 0) {
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numValleys++; // since we just stepped up to sea level
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}
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} else if (ch == 'D') {
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level--;
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}
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}
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return numValleys;
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}
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}
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