Create: 1472-design-browser-history.rs / .ts / .js / .go

go/1472-design-browser-history.go

@@ -0,0 +1,36 @@
+package main
+
+import "math"
+
+func main() {
+
+}
+
+type BrowserHistory struct {
+	history []string
+	current int
+}
+
+func Constructor(homepage string) BrowserHistory {
+	return BrowserHistory{
+		history: []string{homepage},
+		current: 0,
+	}
+}
+
+func (this *BrowserHistory) Visit(url string) {
+	this.history = this.history[0: this.current + 1]
+	this.history = append(this.history, url)
+	this.current++
+}
+
+func (this *BrowserHistory) Back(steps int) string {
+	this.current = int(math.Max(float64(this.current) - float64(steps), 0))
+	return this.history[this.current]
+}
+
+func (this *BrowserHistory) Forward(steps int) string {
+	this.current = int(math.Min(float64(this.current) +float64(steps), float64(len(this.history) - 1)))
+	return this.history[this.current]
+}
+

javascript/1472-design-browser-history.js

@@ -0,0 +1,34 @@
+class BrowserHistory {
+    constructor(homepage) {
+        this.history = [homepage];
+        this.current = 0;
+    }
+
+    /**
+     * @param {string} url
+     * @return {void}
+     */
+
+    visit(url) {
+        this.history[++this.current] = url;
+        this.history.length = this.current + 1;
+    }
+
+    /**
+     * @param {number} steps
+     * @return {string}
+     */
+    back(steps) {
+        this.current = Math.max(this.current - steps, 0);
+        return this.history[this.current];
+    }
+
+    /**
+     * @param {number} steps
+     * @return {string}
+     */
+    forward(steps) {
+        this.current = Math.min(this.current + steps, this.history.length - 1);
+        return this.history[this.current];
+    }
+}

rust/1472-design-browser-history.rs

@@ -0,0 +1,28 @@
+struct BrowserHistory {
+    history: Vec<String>,
+    current: usize,
+}
+
+impl BrowserHistory {
+    fn new(homepage: String) -> Self {
+        Self {
+            history: vec![homepage],
+            current: 0,
+        }
+    }
+
+    fn visit(&mut self, url: String) {
+        self.current += 1;
+        self.history.splice(self.current.., std::iter::once(url));
+    }
+
+    fn back(&mut self, steps: i32) -> String {
+        self.current = self.current.saturating_sub(steps as usize);
+        self.history[self.current].clone()
+    }
+
+    fn forward(&mut self, steps: i32) -> String {
+        self.current = (self.current + steps as usize).min(self.history.len() - 1);
+        self.history[self.current].clone()
+    }
+}

typescript/1472-design-browser-history.ts

@@ -0,0 +1,24 @@
+class BrowserHistory {
+    history: string[];
+    current: number;
+
+    constructor(homepage: string) {
+        this.history = [homepage];
+        this.current = 0;
+    }
+
+    visit(url: string): void {
+        this.history[++this.current] = url;
+        this.history.length = this.current + 1;
+    }
+
+    back(steps: number): string {
+        this.current = Math.max(this.current - steps, 0);
+        return this.history[this.current];
+    }
+
+    forward(steps: number): string {
+        this.current = Math.min(this.current + steps, this.history.length - 1);
+        return this.history[this.current];
+    }
+}