Added description tasks 11-13.

src/main/java/g0001_0100/s0011_container_with_most_water/readme.md

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+11\. Container With Most Water
+
+Medium
+
+Given `n` non-negative integers `a1, a2, ..., an` , where each represents a point at coordinate `(i, ai)`. `n` vertical lines are drawn such that the two endpoints of the line `i` is at `(i, ai)` and `(i, 0)`. Find two lines, which, together with the x-axis forms a container, such that the container contains the most water.
+
+**Notice** that you may not slant the container.
+
+**Example 1:**
+
+![](https://s3-lc-upload.s3.amazonaws.com/uploads/2018/07/17/question_11.jpg)
+
+**Input:** height = \[1,8,6,2,5,4,8,3,7\]
+
+**Output:** 49
+
+**Explanation:** The above vertical lines are represented by array \[1,8,6,2,5,4,8,3,7\]. In this case, the max area of water (blue section) the container can contain is 49. 
+
+**Example 2:**
+
+**Input:** height = \[1,1\]
+
+**Output:** 1 
+
+**Example 3:**
+
+**Input:** height = \[4,3,2,1,4\]
+
+**Output:** 16 
+
+**Example 4:**
+
+**Input:** height = \[1,2,1\]
+
+**Output:** 2 
+
+**Constraints:**
+
+*   `n == height.length`
+*   `2 <= n <= 105`
+*   `0 <= height[i] <= 104`

src/main/java/g0001_0100/s0012_integer_to_roman/readme.md

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+12\. Integer to Roman
+
+Medium
+
+Roman numerals are represented by seven different symbols: `I`, `V`, `X`, `L`, `C`, `D` and `M`.
+
+    Symbol   Value
+     I        1
+     V        5
+     X        10
+     L        50
+     C        100
+     D        500
+     M        1000
+
+For example, `2` is written as `II` in Roman numeral, just two one's added together. `12` is written as `XII`, which is simply `X + II`. The number `27` is written as `XXVII`, which is `XX + V + II`.
+
+Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not `IIII`. Instead, the number four is written as `IV`. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as `IX`. There are six instances where subtraction is used:
+
+*   `I` can be placed before `V` (5) and `X` (10) to make 4 and 9.
+*   `X` can be placed before `L` (50) and `C` (100) to make 40 and 90.
+*   `C` can be placed before `D` (500) and `M` (1000) to make 400 and 900.
+
+Given an integer, convert it to a roman numeral.
+
+**Example 1:**
+
+**Input:** num = 3
+
+**Output:** "III" 
+
+**Example 2:**
+
+**Input:** num = 4
+
+**Output:** "IV" 
+
+**Example 3:**
+
+**Input:** num = 9
+
+**Output:** "IX" 
+
+**Example 4:**
+
+**Input:** num = 58
+
+**Output:** "LVIII"
+
+**Explanation:** L = 50, V = 5, III = 3. 
+
+**Example 5:**
+
+**Input:** num = 1994
+
+**Output:** "MCMXCIV"
+
+**Explanation:** M = 1000, CM = 900, XC = 90 and IV = 4. 
+
+**Constraints:**
+
+*   `1 <= num <= 3999`

src/main/java/g0001_0100/s0013_roman_to_integer/readme.md

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+13\. Roman to Integer
+
+Easy
+
+Roman numerals are represented by seven different symbols: `I`, `V`, `X`, `L`, `C`, `D` and `M`.
+
+    Symbol  Value
+     I       1
+     V       5
+     X       10
+     L       50
+     C       100
+     D       500
+     M       1000
+
+For example, `2` is written as `II` in Roman numeral, just two one's added together. `12` is written as `XII`, which is simply `X + II`. The number `27` is written as `XXVII`, which is `XX + V + II`.
+
+Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not `IIII`. Instead, the number four is written as `IV`. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as `IX`. There are six instances where subtraction is used:
+
+*   `I` can be placed before `V` (5) and `X` (10) to make 4 and 9.
+*   `X` can be placed before `L` (50) and `C` (100) to make 40 and 90.
+*   `C` can be placed before `D` (500) and `M` (1000) to make 400 and 900.
+
+Given a roman numeral, convert it to an integer.
+
+**Example 1:**
+
+**Input:** s = "III"
+
+**Output:** 3 
+
+**Example 2:**
+
+**Input:** s = "IV"
+
+**Output:** 4 
+
+**Example 3:**
+
+**Input:** s = "IX"
+
+**Output:** 9 
+
+**Example 4:**
+
+**Input:** s = "LVIII"
+
+**Output:** 58
+
+**Explanation:** L = 50, V= 5, III = 3. 
+
+**Example 5:**
+
+**Input:** s = "MCMXCIV"
+
+**Output:** 1994
+
+**Explanation:** M = 1000, CM = 900, XC = 90 and IV = 4. 
+
+**Constraints:**
+
+*   `1 <= s.length <= 15`
+*   `s` contains only the characters `('I', 'V', 'X', 'L', 'C', 'D', 'M')`.
+*   It is **guaranteed** that `s` is a valid roman numeral in the range `[1, 3999]`.