435 java solution

java/435-Non-Overlapping-Intervals.java

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+public class Solution {
+    public int eraseOverlapIntervals(int[][] intervals) {
+		int intervalsRemoved = 0;
+
+		//sort by the first vale in the intervals least to greatest
+		Arrays.sort(intervals, (arr1,arr2) -> Integer.compare(arr1[0], arr2[0]));
+		System.out.println(Arrays.deepToString(intervals));
+
+		//get the first interval
+		int[] intervalFirst = intervals[0];
+
+		// then loop through the rest of the intervals
+		for(int i = 1; i < intervals.length; i++){
+			if(firstIntervalwithinSecond(intervalFirst, intervals[i])){
+				//mark first interval to be removed
+				intervalsRemoved++;
+				// determine which interval to remove
+				//remove the interval that ends last
+				if(intervalFirst[1] > intervals[i][1]){
+					intervalFirst = intervals[i];
+				}
+			} else { 
+				intervalFirst = intervals[i];
+			}
+		}
+		return intervalsRemoved;
+	}
+
+	public boolean firstIntervalwithinSecond(int[] intervalFirst, int[] intervalSecond){
+		return intervalSecond[0] < intervalFirst[1];
+	}
+}