diff --git a/problems/0435.无重叠区间.md b/problems/0435.无重叠区间.md
index a92aae7e..ae037f17 100644
--- a/problems/0435.无重叠区间.md
+++ b/problems/0435.无重叠区间.md
@@ -186,27 +186,27 @@ Java：
 class Solution {
     public int eraseOverlapIntervals(int[][] intervals) {
         if (intervals.length < 2) return 0;
+
         Arrays.sort(intervals, new Comparator<int[]>() {
             @Override
             public int compare(int[] o1, int[] o2) {
-                if (o1[0] != o2[0]) {
+                if (o1[1] != o2[1]) {
                     return Integer.compare(o1[1],o2[1]);
                 } else {
-                    return Integer.compare(o2[0],o1[0]);
+                    return Integer.compare(o1[0],o2[0]);
                 }
             }
         });
 
-        int count = 0;
+        int count = 1;
         int edge = intervals[0][1];
         for (int i = 1; i < intervals.length; i++) {
-            if (intervals[i][0] < edge) {
-                count++;
-            } else {
+            if (edge <= intervals[i][0]){
+                count ++; //non overlap + 1
                 edge = intervals[i][1];
             }
         }
-        return count;
+        return intervals.length - count;
     }
 }
 ```
diff --git a/problems/0494.目标和.md b/problems/0494.目标和.md
index 93e90356..63ace2a7 100644
--- a/problems/0494.目标和.md
+++ b/problems/0494.目标和.md
@@ -248,6 +248,7 @@ class Solution {
         for (int i = 0; i < nums.length; i++) sum += nums[i];
         if ((target + sum) % 2 != 0) return 0;
         int size = (target + sum) / 2;
+        if(size < 0) size = -size;
         int[] dp = new int[size + 1];
         dp[0] = 1;
         for (int i = 0; i < nums.length; i++) {