diff --git a/leetcode/README.md b/leetcode/README.md
index fe701f66..7bbd3722 100644
--- a/leetcode/README.md
+++ b/leetcode/README.md
@@ -10,14 +10,17 @@ LeetCode
 |2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/) | [C](./src/2.c)|Medium|
 |3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | [C](./src/3.c)|Medium|
 |4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/) | [C](./src/4.c)|Hard|
+|13|[Roman to Integer](https://leetcode.com/problems/roman-to-integer/) | [C](./src/13.c)|Easy|
 |20|[Valid Parentheses](https://leetcode.com/problems/valid-parentheses/) | [C](./src/20.c)|Easy|
 |21|[Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/) | [C](./src/21.c)|Easy|
 |24|[Swap Nodes in Pairs](https://leetcode.com/problems/swap-nodes-in-pairs/) | [C](./src/24.c)|Medium|
 |26|[Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/) | [C](./src/26.c)|Easy|
 |27|[Remove Element](https://leetcode.com/problems/remove-element/) | [C](./src/27.c)|Easy|
 |28|[Implement strStr()](https://leetcode.com/problems/implement-strstr/) | [C](./src/28.c)|Easy|
+|29|[Divide Two Integers](https://leetcode.com/problems/divide-two-integers/) | [C](./src/29.c)|Medium|
 |35|[Search Insert Position](https://leetcode.com/problems/search-insert-position/) | [C](./src/35.c)|Easy|
 |53|[Maximum Subarray](https://leetcode.com/problems/maximum-subarray/) | [C](./src/53.c)|Easy|
+|66|[Plus One](https://leetcode.com/problems/plus-one/) | [C](./src/66.c)|Easy|
 |82|[Remove Duplicates from Sorted List II](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/) | [C](./src/82.c)|Medium|
 |83|[Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/) | [C](./src/83.c)|Easy|
 |94|[Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/) | [C](./src/94.c)|Medium|
@@ -38,6 +41,7 @@ LeetCode
 |173|[Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/) | [C](./src/173.c)|Medium|
 |190|[Reverse Bits](https://leetcode.com/problems/reverse-bits/) | [C](./src/190.c)|Easy|
 |191|[Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/) | [C](./src/191.c)|Easy|
+|201|[Bitwise AND of Numbers Range](https://leetcode.com/problems/bitwise-and-of-numbers-range/) | [C](./src/201.c)|Medium|
 |203|[Remove Linked List Elements](https://leetcode.com/problems/remove-linked-list-elements/) | [C](./src/203.c)|Easy|
 |206|[Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/) | [C](./src/206.c)|Easy|
 |215|[Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/) | [C](./src/215.c)|Medium|
diff --git a/leetcode/src/13.c b/leetcode/src/13.c
new file mode 100644
index 00000000..0da82cf9
--- /dev/null
+++ b/leetcode/src/13.c
@@ -0,0 +1,49 @@
+int romanToInt(char * s){
+    int romanToInt = 0;
+    for (int i = 0; i < strlen(s); i++) {
+        switch(s[i]) {
+            case 'I':
+                if (i+1 < strlen(s)) {
+                    if (s[i + 1] == 'V' || s[i + 1] == 'X') {
+                        romanToInt -= 1;
+                        break;
+                    }
+                }
+                romanToInt += 1;
+                break;
+            case 'V':
+                romanToInt += 5;
+                break;
+            case 'X':
+                if (i+1 < strlen(s)) {
+                    if (s[i + 1] == 'L' || s[i + 1] == 'C') {
+                        romanToInt -= 10;
+                        break;
+                    }
+                }
+                romanToInt += 10;
+                break;
+            case 'L':
+                romanToInt += 50;
+                break;
+            case 'C':
+                if (i+1 < strlen(s)) {
+                    if (s[i + 1] == 'D' || s[i + 1] == 'M') {
+                        romanToInt -= 100;
+                        break;
+                    }
+                }
+                romanToInt += 100;
+                break;
+            case 'D':
+                romanToInt += 500;
+                break;
+            case 'M':
+                romanToInt += 1000;
+                break;
+            default:
+                break;
+        }
+    }
+    return romanToInt;
+}
\ No newline at end of file
diff --git a/leetcode/src/201.c b/leetcode/src/201.c
new file mode 100644
index 00000000..74a8e77c
--- /dev/null
+++ b/leetcode/src/201.c
@@ -0,0 +1,6 @@
+int rangeBitwiseAnd(int m, int n){
+    while (m < n) {
+        n &= n-1;
+    }
+    return n;
+}
\ No newline at end of file
diff --git a/leetcode/src/29.c b/leetcode/src/29.c
new file mode 100644
index 00000000..d80bd8bb
--- /dev/null
+++ b/leetcode/src/29.c
@@ -0,0 +1,35 @@
+int divide(int dividend, int divisor){
+    int sign = 1;
+    long int output = 0;
+    if (dividend < 0) {
+        sign *= -1;
+
+    } else {
+        dividend *= -1;
+    }
+    if (divisor < 0) {
+        sign *= -1;
+
+    } else {
+        divisor *= -1;
+    }
+    while (dividend <= divisor) {
+        long int tmp = 0;
+        long int div = divisor;
+        while (dividend <= div) {
+            tmp += (tmp+1);
+            dividend -= div;
+            div += div;
+        }
+        if (output >= INT_MAX) {
+            if (sign == -1) {
+                return INT_MIN;
+            } else {
+                return INT_MAX;
+            }
+        }
+        output += tmp;
+    }
+
+    return output * sign;
+}
diff --git a/leetcode/src/66.c b/leetcode/src/66.c
new file mode 100644
index 00000000..bfeec04e
--- /dev/null
+++ b/leetcode/src/66.c
@@ -0,0 +1,22 @@
+/**
+ * Note: The returned array must be malloced, assume caller calls free().
+ */
+int* plusOne(int* digits, int digitsSize, int* returnSize){
+    for (int i = digitsSize-1; i >= 0; i--) {
+        if (digits[i] < 9) {
+            digits[i]++;
+            *returnSize = digitsSize;
+            return digits;
+        } else {
+            digits[i] = 0;
+        }
+    }
+
+    int* newdigit = (int*)malloc((digitsSize+1) * sizeof(int));
+    newdigit[0] = 1;
+    for (int i = 1; i < (digitsSize+1); i++) {
+        newdigit[i] = digits[i-1];
+    }
+    *returnSize = digitsSize+1;
+    return newdigit;
+}
\ No newline at end of file