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fyhhub · Oct 10, 2023 · 315fbad · 315fbad
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diff --git a/code/interview/实现大数相加.js b/code/interview/实现大数相加.js
@@ -1,15 +1,22 @@
 const addStrings = (num1, num2) => {
-  let res = "";
-  let i = num1.length - 1;
-  let j = num2.length - 1;
-  let flag = 0;
-  while (i >= 0 || j >= 0 || flag !== 0) {
-    if (i >= 0) flag += parseInt(num1[i--]);
-    if (j >= 0) flag += parseInt(num2[j--]);
-    // 取余
-    res = (flag % 10) + res;
-    flag = Math.floor(flag / 10);
+  let res = ''
+  let i = num1.length - 1
+  let j = num2.length - 1
+  let flag = 0
+  while(i >= 0 || j >= 0) {
+    let sum = flag;
+    if (i >= 0) sum += parseInt(num1[i--])
+    if (j >= 0) sum += parseInt(num2[j--])
+
+    flag = Math.floor(sum / 10)
+
+    res = sum % 10 + res;
   }
+
+  if (flag > 0) {
+    res = flag + res;
+  }
+
   return res;
 };
 

diff --git a/code/interview/实现并发控制.js b/code/interview/实现并发控制.js
@@ -0,0 +1,85 @@
+async function asyncPool(limit, fns) {
+  const res = []
+  const exec = []
+
+  for (const item of fns) {
+    const p = Promise.resolve().then(() => item())
+
+    res.push(p)
+
+    if (limit <= fns.length) {
+      const execute = p.then(() => {
+        exec.splice(exec.indexOf(execute), 1)
+      })
+      exec.push(p)
+      console.log(exec.length)
+      if (exec.length >= limit) {
+        console.log('达到并发数量', limit)
+        await Promise.race(exec)
+      }
+    }
+  }
+
+  return Promise.all(res)
+}
+
+// 示例测试用例
+async function runTest() {
+  const taskLimit = 3; // 最大并发数
+  const tasks = [
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 1');
+      return 1;
+    },
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 2');
+      return 2;
+    },
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 3');
+      return 3;
+    },
+    async () => {
+      await sleep(500); // 模拟异步任务
+      console.log('执行完成 4');
+      return 4;
+    },
+    async () => {
+      await sleep(2000); // 模拟异步任务
+      console.log('执行完成 5');
+      return 5;
+    },
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 6');
+      return 6;
+    },
+    async () => {
+      await sleep(3000); // 模拟异步任务
+      console.log('执行完成 7');
+      return 7;
+    },
+    async () => {
+      await sleep(500); // 模拟异步任务
+      console.log('执行完成 8');
+      return 8;
+    },
+  ];
+
+  console.log(`Running asyncPool with a limit of ${taskLimit}`);
+  const results = await asyncPool(taskLimit, tasks);
+  console.log(`Results: ${results}`);
+}
+
+// 辅助函数，模拟异步任务
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+// 运行测试用例
+runTest().then(() => {
+  console.log('执行完毕');
+}).catch(console.error);
diff --git a/src/frontend-basic/js/0.1+0.2为什么不等于0.3.md b/src/frontend-basic/js/0.1+0.2为什么不等于0.3.md
@@ -4,4 +4,12 @@ ECMAScript 中的 Number 类型使用 IEEE754 标准来表示整数和浮点数
 
 ECMAScript 采用的就是双精确度，也就是说，会用 `64位` 来储存一个浮点数。
 
-0.1的二进制是无限循环的，0.2的二进制也是无限循环的。所以0.3是不准确的
+0.1的二进制是无限循环的，0.2的二进制也是无限循环的。所以0.3是不准确的
+
+
+## 如何求小数二进制
+0.625 * 2 = 1.25，所以第一位是1。
+小数部分变为0.25。
+0.25 * 2 = 0.5，所以第二位是0。
+小数部分变为0.5。
+0.5 * 2 = 1，所以第三位是1
diff --git a/src/frontend-basic/js/手写题/实现Promise并发控制.md b/src/frontend-basic/js/手写题/实现Promise并发控制.md
@@ -2,45 +2,93 @@
 
 ## 方式一
 ```js
-async function asyncPool(poolLimit, array, iteratorFn) {
-  const ret = [];               //2
-  const executing = [];         //3
-  for (const item of array) {   //4
-    const p = Promise.resolve().then(() => iteratorFn(item));  //5
-    ret.push(p);                //6
-    if (poolLimit <= array.length) { //7
-      const e = p.then(() => executing.splice(executing.indexOf(e), 1)); //8
-      executing.push(e);        //9
-      if (executing.length >= poolLimit) {  //10
-        await Promise.race(executing);      //11
+async function asyncPool(limit, fns) {
+  const res = []
+  const exec = []
+
+  for (const item of fns) {
+    const p = Promise.resolve().then(() => item())
+
+    res.push(p)
+
+    if (limit <= fns.length) {
+      const execute = p.then(() => {
+        exec.splice(exec.indexOf(execute), 1)
+      })
+      exec.push(p)
+      if (exec.length >= limit) {
+        await Promise.race(exec)
       }
     }
   }
-  return Promise.all(ret);     //15
+
+  return Promise.all(res)
 }
 ```
 
 
 ```js
-const curl = (i) => {
-  console.log('开始' + i);
-  return new Promise((resolve) => setTimeout(() => {
-    resolve(i);
-    console.log('结束' + i);
-  }, 1000+Math.random()*1000));
-};
-
-/*
-const curl = (i) => { 
-  console.log('开始' + i);
-  return i;
-};
-*/
-let urls = Array(10).fill(0).map((v,i) => i);
-(async () => {
-    const res = await asyncPool(3, urls, curl);
-    console.log(res);
- })();
+
+// 示例测试用例
+async function runTest() {
+  const taskLimit = 3; // 最大并发数
+  const tasks = [
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 1');
+      return 1;
+    },
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 2');
+      return 2;
+    },
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 3');
+      return 3;
+    },
+    async () => {
+      await sleep(500); // 模拟异步任务
+      console.log('执行完成 4');
+      return 4;
+    },
+    async () => {
+      await sleep(2000); // 模拟异步任务
+      console.log('执行完成 5');
+      return 5;
+    },
+    async () => {
+      await sleep(1000); // 模拟异步任务
+      console.log('执行完成 6');
+      return 6;
+    },
+    async () => {
+      await sleep(3000); // 模拟异步任务
+      console.log('执行完成 7');
+      return 7;
+    },
+    async () => {
+      await sleep(500); // 模拟异步任务
+      console.log('执行完成 8');
+      return 8;
+    },
+  ];
+
+  console.log(`Running asyncPool with a limit of ${taskLimit}`);
+  const results = await asyncPool(taskLimit, tasks);
+  console.log(`Results: ${results}`);
+}
+
+// 辅助函数，模拟异步任务
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+// 运行测试用例
+runTest().then(() => {
+  console.log('执行完毕');
+}).catch(console.error);
 ```
 
 ## 方式二

diff --git a/src/frontend-basic/js/手写题/实现大数相加.md b/src/frontend-basic/js/手写题/实现大数相加.md
@@ -1,18 +1,34 @@
 # 实现大数相加
 
 ```js
-const addStrings = (num1, num2) => {
-  let res = "";
-  let i = num1.length - 1;
-  let j = num2.length - 1;
-  let flag = 0;
-  while (i >= 0 || j >= 0 || flag !== 0) {
-    if (i >= 0) flag += parseInt(num1[i--]);
-    if (j >= 0) flag += parseInt(num2[j--]);
-    // 取余
-    res = (flag % 10) + res;
-    flag = Math.floor(flag / 10);
+const addStrings = (a, b) => {
+  let res = '';
+  let i = a.length - 1;
+  let j = b.length - 1;
+  let flag = 0
+  while(i >= 0 || j >= 0) {
+    let sum = 0;
+    if (i >= 0) sum += parseInt(a[i--])
+    if (j >= 0) sum += parseInt(b[j--])
+    // 加上上次的进位
+    sum += flag;
+
+    // 更新进位
+    flag = Math.floor(sum / 10)
+
+    // 计算值
+    res = sum % 10 + res;
+  }
+
+  // 说明第一位相加 还是有进位
+  if (flag > 0) {
+    res = flag + res;
   }
   return res;
-};
+}
+
+console.log(addStrings('1234', '2345')); // 输出 '3589'
+console.log(addStrings('987654321098765432109876543210', '123456789012345678901234567890')); // 输出 '1111111110111111110111111111000'
+console.log(addStrings('999999', '1')); // 输出 '1000000'
+console.log(addStrings('0', '0')); // 输出 '0'
 ```