rating系统（测试

hydro/lib/rating.js

@@ -0,0 +1,88 @@
+class User {
+    constructor(rank, old, handle = 0) {
+        this.rank = rank;
+        this.old = old;
+        this.seed = 1;
+        this.handle = handle.toString();
+    }
+}
+
+class RatingCalculator {
+    constructor(users) {
+        this.users = [];
+        for (const user of users) {
+            this.users.push(new User(user.rank, user.old, user.uid));
+        }
+    }
+
+    // eslint-disable-next-line class-methods-use-this
+    calP(a, b) {
+        return 1 / (1 + 10 ** ((b.old - a.old) / 400));
+    }
+
+    getExSeed(rating, ownUser) {
+        const exUser = new User(0.0, rating);
+        let result = 1;
+        for (const user of this.users) {
+            if (user !== ownUser) result += this.calP(user, exUser);
+        }
+        return result;
+    }
+
+    calRating(rank, user) {
+        let left = 1;
+        let right = 8000;
+        while (right - left > 1) {
+            const mid = Math.floor((left + right) / 2);
+            if (this.getExSeed(mid, user) < rank) right = mid;
+            else left = mid;
+        }
+        return left;
+    }
+
+    calculate() {
+        // Calculate seed
+        for (let i = 0; i < this.users.length; i++) {
+            this.users[i].seed = 1;
+            for (let j = 0; j < this.users.length; j++) {
+                if (i !== j) {
+                    this.users[i].seed += this.calP(this.users[j], this.users[i]);
+                }
+            }
+        }
+        // Calculate initial delta and sum_delta
+        let sumDelta = 0;
+        for (const user of this.users) {
+            user.delta = (this.calRating(Math.sqrt(user.rank * user.seed), user) - user.old) / 2;
+            sumDelta += user.delta;
+        }
+        // Calculate first inc
+        let inc = Math.floor(-sumDelta / this.users.length) - 1;
+        for (const user of this.users) user.delta += inc;
+        // Calculate second inc
+        this.users = this.users.sort((a, b) => b.old - a.old);
+        const s = Math.min(
+            this.users.length,
+            Math.floor(4 * Math.round(Math.sqrt(this.users.length))),
+        );
+        let sumS = 0;
+        for (let i = 0; i < s; i++) {
+            sumS += this.users[i].delta;
+        }
+        inc = Math.min(Math.max(Math.floor(-sumS / s), -10), 0);
+        // Calculate new rating
+        for (const user of this.users) {
+            user.delta += inc;
+            user.new = user.old + user.delta;
+        }
+        this.users = this.users.sort((a, b) => a.rank - b.rank);
+        return this.users;
+    }
+}
+
+function calculate(users) {
+    const calculator = new RatingCalculator(users);
+    return calculator.calculate();
+}
+
+module.exports = calculate;