feat(codes/cpp): revert the changes size_t back to int

codes/cpp/chapter_array_and_linkedlist/list.cpp

@@ -48,8 +48,8 @@ int main() {
     PrintUtil::printVector(list);
 
     /* 通过索引遍历列表 */
-    size_t count = 0;
-    for (size_t i = 0; i < list.size(); i++) {
+    int count = 0;
+    for (int i = 0; i < list.size(); i++) {
         count++;
     }
 

codes/cpp/chapter_computational_complexity/worst_best_time_complexity.cpp

@@ -22,7 +22,7 @@ vector<int> randomNumbers(int n) {
 
 /* 查找数组 nums 中数字 1 所在索引 */
 int findOne(vector<int>& nums) {
-    for (size_t i = 0; i < nums.size(); i++) {
+    for (int i = 0; i < nums.size(); i++) {
         if (nums[i] == 1)
             return i;
     }

codes/cpp/chapter_searching/hashing_search.cpp

@@ -33,7 +33,7 @@ int main() {
     vector<int> nums = { 1, 5, 3, 2, 4, 7, 5, 9, 10, 8 };
     // 初始化哈希表
     unordered_map<int, int> map;
-    for (size_t i = 0; i < nums.size(); i++) {
+    for (int i = 0; i < nums.size(); i++) {
         map[nums[i]] = i;  // key: 元素，value: 索引
     }
     int index = hashingSearch(map, target);

codes/cpp/chapter_searching/linear_search.cpp

@@ -9,7 +9,7 @@
 /* 线性查找（数组） */
 int linearSearch(vector<int>& nums, int target) {
     // 遍历数组
-    for (size_t i = 0; i < nums.size(); i++) {
+    for (int i = 0; i < nums.size(); i++) {
         // 找到目标元素，返回其索引
         if (nums[i] == target)
             return i;

codes/cpp/chapter_stack_and_queue/linkedlist_queue.cpp

@@ -68,7 +68,7 @@ public:
     vector<int> toVector() {
         ListNode* node = front;
         vector<int> res(size());
-        for (size_t i = 0; i < res.size(); i++) {
+        for (int i = 0; i < res.size(); i++) {
             res[i] = node->val;
             node = node->next;
         }