diff --git "a/\346\236\227\346\242\205\346\240\252/2.21\344\275\234\344\270\232Steam/Steam.js" "b/\346\236\227\346\242\205\346\240\252/2.21\344\275\234\344\270\232Steam/Steam.js"
new file mode 100644
index 0000000000000000000000000000000000000000..16f236560ea9dda1c81b8ba100d4e332b44de9b8
--- /dev/null
+++ "b/\346\236\227\346\242\205\346\240\252/2.21\344\275\234\344\270\232Steam/Steam.js"
@@ -0,0 +1,38 @@
+let fs=require("fs");
+function big(){
+    let str ="zcvbnmlikjghfdaqwddfrgthuykjkgjnfjdcg"
+    let fd =fs.openSync("./big.txt","a");
+    for(let i=0;i<1000000; i++){
+        let start = Math.floor(Math.random()*(str.length));
+        let end = Math.floor(Math.random()*(str.length));
+        if(start > end){
+            let tem =start;
+            start = end;
+            end =tem;
+        }
+        if(start==end) continue;
+
+        let temstring =str.slice(start,end);
+
+        fs.writeSync(fd,temstring);
+    }
+    fs.closeSync(fd);
+}
+let read=fs.createReadStream("./big.txt");
+let array=[];
+read.on("data",(chunk)=>{
+
+    let str =chunk.toString();
+    for(let i=0;i<str.length;i++){
+
+        if(array[str[i]]==undefined){
+            array[str[i]]=1;
+        }else{
+            array[str[i]] += 1;
+        }
+    }
+});
+read.on("end",()=>{
+    console.log(array);
+});
+