Update README.md

README.md

@@ -51,4 +51,45 @@ size_categories:
 
 1.4k pairs dataset of math problems and their solutions in Japanese scraped from [OnlineMathContest](https://onlinemathcontest.com/).
 
-Last updated at: 2024/03/23
+Note: All problems and solutions have source urls (the `url` field), and their authors and OnlineMathContest own the copyrights.
+
+## Dataset fields
+
+- `contest`: Name of the contest that contains each problem.
+- `contest_url`: The url of a contest that contains each problem.
+- `url`: The url of each problem.
+- `alphabet`: The alphabet of each problem. (e.g. `A`, `B`, ...)
+- `name`: The name of each problem.
+- `score`: The number of points earned for solving each problem.
+- `correct`: The number of people who could solve each problem during their contest.
+- `total`: The total number of people who tried to solve each problem during their contest.
+- `editorials`: The solution and explanation of each problem by the author or volunteers.
+  - `url`: The url of each solution.
+  - `name`: The name of each solution. (e.g. `公式解説`)
+  - `content`: The content text of each solution. This might be null sometimes.
+- `task_content`: The content text of each problem.
+
+`editorials.content` and `task_content` uses Markdown and [KaTeX](https://katex.org/) markup.
+
+## Example
+
+```json
+{
+    "contest": "OMC215 (お茶ゼミ√+杯)",
+    "contest_url": "https://onlinemathcontest.com/contests/all?page=1",
+    "url": "https://onlinemathcontest.com/contests/omc215/tasks/9284",
+    "alphabet": "A",
+    "name": "OMC215(A)",
+    "score": "100",
+    "correct": 387,
+    "total": 412,
+    "editorials": [
+        {
+            "content": "$$\\frac{a^2-1001a+1001^2}{b^2-1001b+1001^2}\\leq\\frac{\\max\\lbrace a^2-1001a+1001^2\\rbrace}{\\min\\lbrace b^2-1001b+1001^2\\rbrace}$$\r\nであり，等号が成立するのは $a=1,1000$ かつ $b=500,501$ のときであるので解答すべき値は\r\n$$(1+500)+(1+501)+(1000+500)+(1000+501)=\\mathbf{4004}.$$",
+            "text": "公式解説",
+            "url": "https://onlinemathcontest.com/contests/omc215/editorial/9284"
+        }
+    ],
+    "task_content": "　 $1\\leq a\\leq 1000, ~ 1\\leq b\\leq 1000$ なる整数 $a,b$ について，\r\n$$\\frac{a^2-1001a+1001^2}{b^2-1001b+1001^2}$$\r\nがありうる最大の値をとるとき，$a+b$ としてありうる値の総和を求めてください．"
+}
+```