[HAI] home work leetcode WIP

https://leetcode.com/problems/string-compression/submissions/1451041094/

lib/compress/compress.test.ts

@@ -0,0 +1,36 @@
+import { describe, it, expect } from "vitest";
+import { compress } from "./compress.ts";
+
+describe("compress", () => {
+
+  it(`["a", "a", "b", "b", "c", "c", "c"] => a2b2c3 => 6`, () => {
+    const arr = ["a", "a", "b", "b", "c", "c", "c"];
+    expect(compress(arr)).toBe(6);
+  });
+
+  it(`["a"] => a => 1`, () => {
+    const arr = ["a"];
+    expect(compress(arr)).toBe(1);
+  });
+
+  it(`["a","b","b","b","b","b","b","b","b","b","b","b","b"] => ab12 => 4`, () => {
+    const arr = ["a", "b", "b", "b", "b", "b", "b", "b", "b", "b", "b", "b", "b"];
+    expect(compress(arr)).toBe(4);
+  });
+
+  it(`["a","a","a","b","b","a","a"] => a3b2a2 => 6`, () => {
+    const arr = ["a", "a", "a", "b", "b", "a", "a"];
+    expect(compress(arr)).toBe(6);
+  });
+
+  it(`["a","a","a","a","a","b"] => a5b => 3`, () => {
+    const arr = ["a", "a", "a", "a", "a", "b"];
+    expect(compress(arr)).toBe(3);
+  });
+
+  it(`["a","a","a","b","b","b","c","c","c"] => a3b3c3 => 6`, () => {
+    const arr = ["a", "a", "a", "b", "b", "b", "c", "c", "c"];
+    expect(compress(arr)).toBe(6);
+  });
+
+});

lib/compress/compress.ts

@@ -0,0 +1,70 @@
+// export function compress(chars: string[]) {
+//   let L = 0;
+//   let R = 1;
+//   const N = chars.length;
+//   let result = "";
+//   let currentCounter = 1;
+
+//   while (L <= N && R <= N) {
+//     const curL = chars[L];
+//     const curR = chars[R];
+
+
+//     if (curL !== curR || curR === undefined) {
+//       result += curL;
+//       if (currentCounter > 1) {
+//         result += currentCounter;
+//         currentCounter = 1;
+//       }
+//       L = R;
+//     }
+
+//     if (curL === curR) {
+//       currentCounter++;
+//     }
+
+//     R++
+//   }
+
+//   return result.length;
+// };
+
+export function compress(chars: string[]) {
+  let L = 0;
+  let R = 1;
+  const N = chars.length;
+  let currentCounter = 1;
+
+  while (L <= N && R <= N) {
+    const curL = chars[L];
+    const curR = chars[R];
+
+
+    if (curL !== curR || curR === undefined) {
+      if (currentCounter > 1) {
+        [...("" + currentCounter)].forEach((item, i) => {
+          chars[L + 1 + i] = item;
+        });
+        currentCounter = 1;
+      }
+      L = R;
+    }
+
+    if (curL === curR) {
+      currentCounter++;
+      chars[R] = "";
+    }
+
+    R++
+  }
+
+  for (let [key, value] of Object.entries(chars)) {
+    if (value === "") {
+      chars.splice(+key, 1)
+    }
+  }
+
+  console.log({ chars })
+
+  return chars.filter(item => item).length;
+};

lib/compress/index.ts

@@ -0,0 +1,3 @@
+import { compress } from "./compress";
+
+export default compress;