Re-translate the Japanese version (#1871)

* Retranslate Japanese docs with GPT-5.4

* Retranslate Japanese code with GPT-5.4

ja/codes/c/chapter_searching/two_sum.c

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+/**
+ * File: two_sum.c
+ * Created Time: 2023-01-19
+ * Author: Reanon (793584285@qq.com)
+ */
+
+#include "../utils/common.h"
+
+/* 方法 1：総当たり列挙 */
+int *twoSumBruteForce(int *nums, int numsSize, int target, int *returnSize) {
+    for (int i = 0; i < numsSize; ++i) {
+        for (int j = i + 1; j < numsSize; ++j) {
+            if (nums[i] + nums[j] == target) {
+                int *res = malloc(sizeof(int) * 2);
+                res[0] = i, res[1] = j;
+                *returnSize = 2;
+                return res;
+            }
+        }
+    }
+    *returnSize = 0;
+    return NULL;
+}
+
+/* ハッシュテーブル */
+typedef struct {
+    int key;
+    int val;
+    UT_hash_handle hh; // uthash.h を用いて実装
+} HashTable;
+
+/* ハッシュテーブルを検索する */
+HashTable *find(HashTable *h, int key) {
+    HashTable *tmp;
+    HASH_FIND_INT(h, &key, tmp);
+    return tmp;
+}
+
+/* ハッシュテーブルに要素を挿入する */
+void insert(HashTable **h, int key, int val) {
+    HashTable *t = find(*h, key);
+    if (t == NULL) {
+        HashTable *tmp = malloc(sizeof(HashTable));
+        tmp->key = key, tmp->val = val;
+        HASH_ADD_INT(*h, key, tmp);
+    } else {
+        t->val = val;
+    }
+}
+
+/* 方法 2：補助ハッシュテーブル */
+int *twoSumHashTable(int *nums, int numsSize, int target, int *returnSize) {
+    HashTable *hashtable = NULL;
+    for (int i = 0; i < numsSize; i++) {
+        HashTable *t = find(hashtable, target - nums[i]);
+        if (t != NULL) {
+            int *res = malloc(sizeof(int) * 2);
+            res[0] = t->val, res[1] = i;
+            *returnSize = 2;
+            return res;
+        }
+        insert(&hashtable, nums[i], i);
+    }
+    *returnSize = 0;
+    return NULL;
+}
+
+/* Driver Code */
+int main() {
+    // ======= Test Case =======
+    int nums[] = {2, 7, 11, 15};
+    int target = 13;
+    // ====== Driver Code ======
+    int returnSize;
+    int *res = twoSumBruteForce(nums, sizeof(nums) / sizeof(int), target, &returnSize);
+    // 方法 1
+    printf("方法1 res = ");
+    printArray(res, returnSize);
+
+    // 方法 2
+    res = twoSumHashTable(nums, sizeof(nums) / sizeof(int), target, &returnSize);
+    printf("方法2 res = ");
+    printArray(res, returnSize);
+
+    return 0;
+}