0005 and 0006 done in c language

Author: pranjal030404

solution/0000-0099/0005.Longest Palindromic Substring/README.md

@@ -527,6 +527,56 @@ 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 -->

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 -->

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;
+}

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 -->

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 -->

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;
+}