diff --git a/solution/0000-0099/0005.Longest Palindromic Substring/README.md b/solution/0000-0099/0005.Longest Palindromic Substring/README.md
index 11a6b7df01a67..e4a000d7aa164 100644
--- a/solution/0000-0099/0005.Longest Palindromic Substring/README.md	
+++ b/solution/0000-0099/0005.Longest Palindromic Substring/README.md	
@@ -527,6 +527,55 @@ class Solution {
 }
 ```
 
+#### c
+
+```c
+char *longestPalindrome(char *s) {
+  int n = strlen(s);
+  if (n == 0) {
+    char *result = malloc(1);
+    result[0] = '\0';
+    return result;
+  }
+
+  bool dp[n][n];
+  memset(dp, 0, sizeof(dp));
+
+  int start = 0, max_len = 1;
+
+  for (int i = 0; i < n; i++) {
+    dp[i][i] = true;
+  }
+
+  for (int i = 0; i < n - 1; i++) {
+    if (s[i] == s[i + 1]) {
+      dp[i][i + 1] = true;
+      start = i;
+      max_len = 2;
+    }
+  }
+
+  // Check for lengths > 2
+  for (int len = 3; len <= n; len++) {
+    for (int i = 0; i < n - len + 1; i++) {
+      int j = i + len - 1;
+      if (s[i] == s[j] && dp[i + 1][j - 1]) {
+        dp[i][j] = true;
+        if (len > max_len) {
+          start = i;
+          max_len = len;
+        }
+      }
+    }
+  }
+  char *result = malloc(max_len + 1);
+  strncpy(result, s + start, max_len);
+  result[max_len] = '\0';
+  return result;
+}
+
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/0000-0099/0005.Longest Palindromic Substring/README_EN.md b/solution/0000-0099/0005.Longest Palindromic Substring/README_EN.md
index 4ac2610fb4e8e..8b39b068c345c 100644
--- a/solution/0000-0099/0005.Longest Palindromic Substring/README_EN.md	
+++ b/solution/0000-0099/0005.Longest Palindromic Substring/README_EN.md	
@@ -525,6 +525,55 @@ class Solution {
 }
 ```
 
+#### C
+
+```c
+char *longestPalindrome(char *s) {
+  int n = strlen(s);
+  if (n == 0) {
+    char *result = malloc(1);
+    result[0] = '\0';
+    return result;
+  }
+
+  bool dp[n][n];
+  memset(dp, 0, sizeof(dp));
+
+  int start = 0, max_len = 1;
+
+  for (int i = 0; i < n; i++) {
+    dp[i][i] = true;
+  }
+
+  for (int i = 0; i < n - 1; i++) {
+    if (s[i] == s[i + 1]) {
+      dp[i][i + 1] = true;
+      start = i;
+      max_len = 2;
+    }
+  }
+
+  // Check for lengths > 2
+  for (int len = 3; len <= n; len++) {
+    for (int i = 0; i < n - len + 1; i++) {
+      int j = i + len - 1;
+      if (s[i] == s[j] && dp[i + 1][j - 1]) {
+        dp[i][j] = true;
+        if (len > max_len) {
+          start = i;
+          max_len = len;
+        }
+      }
+    }
+  }
+  char *result = malloc(max_len + 1);
+  strncpy(result, s + start, max_len);
+  result[max_len] = '\0';
+  return result;
+}
+
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/0000-0099/0005.Longest Palindromic Substring/Solution.c b/solution/0000-0099/0005.Longest Palindromic Substring/Solution.c
new file mode 100644
index 0000000000000..26592c3a40353
--- /dev/null
+++ b/solution/0000-0099/0005.Longest Palindromic Substring/Solution.c	
@@ -0,0 +1,45 @@
+
+
+char* longestPalindrome(char* s) {
+    int n = strlen(s);
+    if (n == 0) {
+        char* result = malloc(1);
+        result[0] = '\0';
+        return result;
+    }
+
+    bool dp[n][n];
+    memset(dp, 0, sizeof(dp));
+
+    int start = 0, max_len = 1;
+
+    for (int i = 0; i < n; i++) {
+        dp[i][i] = true;
+    }
+
+    for (int i = 0; i < n - 1; i++) {
+        if (s[i] == s[i + 1]) {
+            dp[i][i + 1] = true;
+            start = i;
+            max_len = 2;
+        }
+    }
+
+    // Check for lengths > 2
+    for (int len = 3; len <= n; len++) {
+        for (int i = 0; i < n - len + 1; i++) {
+            int j = i + len - 1;
+            if (s[i] == s[j] && dp[i + 1][j - 1]) {
+                dp[i][j] = true;
+                if (len > max_len) {
+                    start = i;
+                    max_len = len;
+                }
+            }
+        }
+    }
+    char* result = malloc(max_len + 1);
+    strncpy(result, s + start, max_len);
+    result[max_len] = '\0';
+    return result;
+}
diff --git a/solution/0000-0099/0006.Zigzag Conversion/README.md b/solution/0000-0099/0006.Zigzag Conversion/README.md
index c12bad03a22aa..172268afc5ed9 100644
--- a/solution/0000-0099/0006.Zigzag Conversion/README.md	
+++ b/solution/0000-0099/0006.Zigzag Conversion/README.md	
@@ -493,6 +493,40 @@ class Solution {
 }
 ```
 
+#### C
+
+```C
+char *convert(char *s, int numRows) {
+  if (numRows == 1 || numRows >= strlen(s)) {
+    char *result = malloc(strlen(s) + 1);
+    strcpy(result, s);
+    return result;
+  }
+  char **rows = malloc(numRows * sizeof(char *));
+  for (int i = 0; i < numRows; i++) {
+    rows[i] = malloc(strlen(s) + 1);
+    rows[i][0] = '\0';
+  }
+  int currentRow = 0;
+  int goingDown = 0;
+  for (int i = 0; s[i] != '\0'; i++) {
+    strncat(rows[currentRow], &s[i], 1);
+    if (currentRow == 0 || currentRow == numRows - 1) {
+      goingDown = !goingDown;
+    }
+    currentRow += goingDown ? 1 : -1;
+  }
+  char *result = malloc(strlen(s) + 1);
+  result[0] = '\0';
+  for (int i = 0; i < numRows; i++) {
+    strcat(result, rows[i]);
+    free(rows[i]);
+  }
+  free(rows);
+  return result;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/0000-0099/0006.Zigzag Conversion/README_EN.md b/solution/0000-0099/0006.Zigzag Conversion/README_EN.md
index 04390da8f24e7..45bce03f21a1e 100644
--- a/solution/0000-0099/0006.Zigzag Conversion/README_EN.md	
+++ b/solution/0000-0099/0006.Zigzag Conversion/README_EN.md	
@@ -491,6 +491,40 @@ class Solution {
 }
 ```
 
+####
+
+```c
+char *convert(char *s, int numRows) {
+  if (numRows == 1 || numRows >= strlen(s)) {
+    char *result = malloc(strlen(s) + 1);
+    strcpy(result, s);
+    return result;
+  }
+  char **rows = malloc(numRows * sizeof(char *));
+  for (int i = 0; i < numRows; i++) {
+    rows[i] = malloc(strlen(s) + 1);
+    rows[i][0] = '\0';
+  }
+  int currentRow = 0;
+  int goingDown = 0;
+  for (int i = 0; s[i] != '\0'; i++) {
+    strncat(rows[currentRow], &s[i], 1);
+    if (currentRow == 0 || currentRow == numRows - 1) {
+      goingDown = !goingDown;
+    }
+    currentRow += goingDown ? 1 : -1;
+  }
+  char *result = malloc(strlen(s) + 1);
+  result[0] = '\0';
+  for (int i = 0; i < numRows; i++) {
+    strcat(result, rows[i]);
+    free(rows[i]);
+  }
+  free(rows);
+  return result;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/0000-0099/0006.Zigzag Conversion/Solution.c b/solution/0000-0099/0006.Zigzag Conversion/Solution.c
new file mode 100644
index 0000000000000..0c23f5da5b410
--- /dev/null
+++ b/solution/0000-0099/0006.Zigzag Conversion/Solution.c	
@@ -0,0 +1,29 @@
+char *convert(char *s, int numRows) {
+  if (numRows == 1 || numRows >= strlen(s)) {
+    char *result = malloc(strlen(s) + 1);
+    strcpy(result, s);
+    return result;
+  }
+  char **rows = malloc(numRows * sizeof(char *));
+  for (int i = 0; i < numRows; i++) {
+    rows[i] = malloc(strlen(s) + 1);
+    rows[i][0] = '\0';
+  }
+  int currentRow = 0;
+  int goingDown = 0;
+  for (int i = 0; s[i] != '\0'; i++) {
+    strncat(rows[currentRow], &s[i], 1);
+    if (currentRow == 0 || currentRow == numRows - 1) {
+      goingDown = !goingDown;
+    }
+    currentRow += goingDown ? 1 : -1;
+  }
+  char *result = malloc(strlen(s) + 1);
+  result[0] = '\0';
+  for (int i = 0; i < numRows; i++) {
+    strcat(result, rows[i]);
+    free(rows[i]);
+  }
+  free(rows);
+  return result;
+}
\ No newline at end of file