g2501_2600.s2559_count_vowel_strings_in_ranges.Solution Maven / Gradle / Ivy
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Java-based LeetCode algorithm problem solutions, regularly updated
package g2501_2600.s2559_count_vowel_strings_in_ranges;
// #Medium #Array #String #Prefix_Sum #2023_08_19_Time_4_ms_(99.59%)_Space_85.6_MB_(78.46%)
public class Solution {
private boolean validWord(String s) {
char cStart = s.charAt(0);
char cEnd = s.charAt(s.length() - 1);
boolean flag1 =
cStart == 'a' || cStart == 'e' || cStart == 'i' || cStart == 'o' || cStart == 'u';
boolean flag2 = cEnd == 'a' || cEnd == 'e' || cEnd == 'i' || cEnd == 'o' || cEnd == 'u';
return flag1 && flag2;
}
public int[] vowelStrings(String[] words, int[][] queries) {
int[] prefixArr = new int[words.length];
prefixArr[0] = validWord(words[0]) ? 1 : 0;
for (int i = 1; i < words.length; ++i) {
if (validWord(words[i])) {
prefixArr[i] = prefixArr[i - 1] + 1;
} else {
prefixArr[i] = prefixArr[i - 1];
}
}
int[] res = new int[queries.length];
for (int i = 0; i < queries.length; ++i) {
int upperBound = queries[i][1];
int lowerBound = queries[i][0];
int val =
(lowerBound == 0)
? prefixArr[upperBound]
: prefixArr[upperBound] - prefixArr[lowerBound - 1];
res[i] = val;
}
return res;
}
}