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Java Solution for LeetCode algorithm problems, continually updating
package g0401_0500.s0435_non_overlapping_intervals;
// #Medium #Array #Dynamic_Programming #Sorting #Greedy #Data_Structure_II_Day_4_Array
// #2022_07_16_Time_96_ms_(47.37%)_Space_106.6_MB_(6.15%)
import java.util.Arrays;
public class Solution {
/*
* This is sorting my starting time, the key here is that we'll want to update end time when an
* erasure is needed: we use the smaller end time instead of the bigger one which is more likely
* to overlap with others.
*/
public int eraseOverlapIntervals(int[][] intervals) {
Arrays.sort(intervals, (a, b) -> a[0] != b[0] ? a[0] - b[0] : a[1] - b[1]);
int erasures = 0;
int end = intervals[0][1];
for (int i = 1; i < intervals.length; i++) {
if (intervals[i][0] < end) {
erasures++;
end = Math.min(end, intervals[i][1]);
} else {
end = intervals[i][1];
}
}
return erasures;
}
}