Refine

Signed-off-by: begeekmyfriend <begeekmyfriend@gmail.com>

Author: begeekmyfriend

001_two_sum/two_sum.c

@@ -47,9 +47,10 @@ int main(void)
     //int nums[] = {0,4,3,0};
     //int target = 0;
     int nums[] = { 3, 2, 3 };
-    int count = sizeof(nums) / sizeof(*nums);
+    int size = sizeof(nums) / sizeof(*nums);
     int target = 6;
-    int *indexes = twosum(nums, count, target);
+    int count = 0;
+    int *indexes = twosum(nums, size, target, &count);
     if (indexes != NULL) {
         printf("%d %d\n", indexes[0], indexes[1]);
     } else {

001_two_sum/two_sum.py

@@ -0,0 +1,11 @@
+class Solution:
+    def twoSum(self, nums, target):
+        h = {}
+        for i, n in enumerate(nums):
+            other = target - n
+            if other not in h:
+                h[n] = i
+            else:
+                return [h[other], i]
+
+print(Solution().twoSum([-1, -2, -3, -4, -5], -8))

002_add_two_numbers/add_two_numbers.c

@@ -10,48 +10,50 @@ struct ListNode {
 
 static struct ListNode* addTwoNumbers(struct ListNode* l1, struct ListNode* l2)
 {
-    int carry_num = 0;
-    int first = 1;
-    struct ListNode *res = NULL;
-    struct ListNode *p = NULL;
-    struct ListNode *prev = p;
+    int carry = 0;
+    struct ListNode dummy;
+    struct ListNode *p = l1, *prev = &dummy;
 
-    while (l1 != NULL || l2 != NULL || carry_num) {
+    dummy.next = p;
+    while (l1 != NULL || l2 != NULL) {
         int sum = 0;
-        int last_carry = carry_num;
+        int last_carry = carry;
+
         if (l1 != NULL) {
+            if (p == NULL) {
+                /* p never be NULL */
+                prev->next = l1;
+                p = l1;
+            }
             sum += l1->val;
             l1 = l1->next;
         }
+
         if (l2 != NULL) {
+            if (p == NULL) {
+                /* p never be NULL */
+                prev->next = l2;
+                p = l2;
+            }
             sum += l2->val;
             l2 = l2->next;
         }
-        if (sum >= 10) {
-            sum -= 10;
-            carry_num = 1;
-        } else {
-            carry_num = 0;
-        }
+        
+        sum += last_carry;
+        carry = sum / 10;
+        p->val = sum % 10;
+        prev = p;
+        p = p->next;
+    }
 
+    if (carry) {
         p = malloc(sizeof(*p));
-        if (first) {
-             res = p;
-             first = 0;
-        }
-        p->val = sum + last_carry;
-        if (p->val >= 10) {
-            p->val -= 10;
-            carry_num = 1;
-        }
+        p->val = carry;
         p->next = NULL;
-        if (prev != NULL) {
-             prev->next = p;
-        }
-        prev = p;
+        prev->next = p;
     }
-
-    return res;
+    
+    return dummy.next;
 }
 
 static struct ListNode *node_build(const char *digits)