mainshi

面试题/头条.js

@@ -0,0 +1,78 @@
+/*
+class Manager {
+    constructor(max) {
+      this.max = max;
+    }
+  
+    add(fn) { // fn: () => Promise<any>
+  
+    }
+  }
+  
+  
+  const wrapper = (str, time) => {
+    return () => {
+          return new Promise(res => {
+              setTimeout(() => {
+                  console.log(str);
+  
+                  res();
+              }, time)
+          })
+  
+    }
+  }
+  
+  const m = new Manager(2);
+  
+  m.add(wrapper('a', 1000));
+  m.add(wrapper('b', 500));
+  m.add(wrapper('c', 300));
+  
+  0  start
+  500  b
+  800  c
+  1000  a
+  */
+
+
+  class Manager {
+      constructor(max) {
+        this.max = max
+        this.cbs = []
+        this.queen = []
+      }
+      add(fn) {
+        if(this.cbs.length < this.max) {
+            this.cbs.push(fn)
+            fn().then(res => {
+                let index = this.cbs.indexOf(fn)
+                this.cbs.splice(index, 1)
+                if(this.queen.length > 0) {
+                    this.add(this.queen.shift())
+                }
+            })
+        } else {
+            this.queen.push(fn)
+        }
+      } 
+  }
+
+  const wrapper = (str, time) => {
+    return () => {
+          return new Promise(res => {
+              setTimeout(() => {
+                  console.log(str);
+
+                  res();
+              }, time)
+          })
+
+    }
+  }
+
+  const m = new Manager(2);
+
+  m.add(wrapper('a', 1000));
+  m.add(wrapper('b', 500));
+  m.add(wrapper('c', 300));