commit

Author: 王俊超

.idea/modules.xml

@@ -0,0 +1,27 @@
+/**
+ * @author: wangjunchao(王俊超)
+ * @time: 2018-09-28 15:18
+ **/
+public class Solution {
+    public int firstMissingPositive(int[] nums) {
+        int n = nums.length;
+        for (int i = 0; i < n; i++) {
+            while (nums[i] > 0 && nums[i] <= n && nums[i] != nums[nums[i] - 1]) {
+                swap(nums, i, nums[i] - 1);
+            }
+        }
+        for (int i = 0; i < n; i++) {
+            if (nums[i] != i + 1) {
+                return i + 1;
+            }
+        }
+
+        return n + 1;
+    }
+
+    private void swap(int[] nums, int i, int j) {
+        int temp = nums[i];
+        nums[i] = nums[j];
+        nums[j] = temp;
+    }
+}