"Excel Sheet Column Title"

Author: lennylxx

README.md

@@ -26,7 +26,7 @@ them with C++ Language.
 | 171 | [Excel Sheet Column Number]                                  |                    |
 | 170 | [Two Sum III - Data structure design]                        |                    |
 | 169 | [Majority Element]                                           | [C](src/169.c)     |
-| 168 | [Excel Sheet Column Title]                                   |                    |
+| 168 | [Excel Sheet Column Title]                                   | [C](src/168.c)     |
 | 167 | [Two Sum II - Input array is sorted]                         |                    |
 | 166 | [Fraction to Recurring Decimal]                              |                    |
 | 165 | [Compare Version Numbers]                                    | [C](src/165.c)     |

src/168.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char *convertToTitle(int n) {
+    char *ans = (char *)calloc(10, sizeof(char));
+
+    int i;
+    i = 0;
+    while (n > 0) {
+        int t = n % 26;
+        if (t == 0) { t = 26; ans[i] = 'Z'; }
+        else { ans[i] = t + 'A' - 1; }
+        n -= t;
+        n /= 26;
+        i++;
+    }
+    /* reverse string */
+    int j = strlen(ans) - 1;
+    i = 0;
+    while (i < j) {
+        char t = ans[i];
+        ans[i] = ans[j];
+        ans[j] = t;
+        i++;
+        j--;
+    }
+
+    return ans;
+}
+
+int main() {
+    int n = 26;
+    printf("%s\n", convertToTitle(n));
+    return 0;
+}