lcof2: add 6, 8, 9

Author: Ijiamuyu

lcof2/剑指 Offer II 006. 排序数组中两个数字之和/Solution.cpp

@@ -9,4 +9,25 @@ class Solution {
             }
         }
     }
+};
+
+
+//leetcode题目，下标不同
+class Solution {
+public:
+    vector<int> twoSum(vector<int>& numbers, int target) {
+        vector<int> ans;
+        for(int i = 0; i < numbers.size(); i++)
+        {
+            int x = target - numbers[i];
+            int j = lower_bound(numbers.begin() + i + 1, numbers.end(), x) - numbers.begin();
+            if( j < numbers.size() && numbers[j] == x)
+            {
+                ans.push_back(i + 1);
+                ans.push_back(j + 1);
+                break;
+            }
+        }
+        return ans;
+    }
 };

lcof2/剑指 Offer II 008. 和大于等于 target 的最短子数组/Solution.cpp

@@ -14,4 +14,21 @@ class Solution {
         }
         return ans == inf ? 0 : ans;
     }
+};
+
+class Solution {
+public:
+    int minSubArrayLen(int target, vector<int>& nums) {
+        int length = INT_MAX, sum = 0;
+        for(int fast = 0, slow = 0; fast < nums.size(); fast++)
+        {
+            sum += nums[fast];
+            while(sum >= target)
+            {
+                length = min(length, fast - slow + 1);
+                sum -= nums[slow++];
+            }
+        }
+        return length == INT_MAX ? 0 : length;
+    }
 };

lcof2/剑指 Offer II 009. 乘积小于 K 的子数组/Solution.cpp

@@ -12,4 +12,24 @@ class Solution {
         }
         return ans;
     }
-};
+};
+
+class Solution {
+public:
+    int numSubarrayProductLessThanK(vector<int>& nums, int k) {
+        int ans = 0, product = 1;
+        for(int left = 0, right = 0; right < nums.size(); right++)
+        {
+            product *= nums[right];
+            while(left <= right && product >= k)
+            {
+                product /= nums[left++];
+            }
+            if(left <= right)
+            {
+                ans += (right - left + 1);
+            }
+        }
+        return ans;
+    }
+};