Hash - linear probe

Author: mechaniccoder

hash/linear_probing.ts

@@ -0,0 +1,72 @@
+const hashTableSize = 13;
+
+const hashTable: (string | number)[] = Array(hashTableSize).fill(null);
+
+function hashFun(str: string) {
+  let result = 0;
+  for (let i = 0; i < str.length; i++) {
+    result += str.charCodeAt(i);
+  }
+
+  result %= hashTableSize;
+  return Math.floor(result);
+}
+
+function addToHashTable(item: { key: string; value: string | number }) {
+  const hashAddr = hashFun(item.key);
+
+  let i = hashAddr;
+  while (hashTable[i] !== null) {
+    if (hashTable[i] === item.value) {
+      throw new Error("Duplicated item");
+    }
+
+    i = (i + 1) % hashTableSize;
+    if (i === hashAddr) {
+      throw new Error("Hash table full");
+    }
+  }
+
+  hashTable[i] = item.value;
+}
+
+const a = addToHashTable({ key: "hi", value: 1 });
+
+function hashSearch(item: { key: string; value: number }) {
+  const hashAddr = hashFun(item.key);
+
+  let i = hashAddr;
+  while (hashTable[i]) {
+    if (hashTable[i] === item.value) {
+      return hashTable[i];
+    }
+
+    i = (i + 1) % hashTableSize;
+
+    if (hashAddr === i) {
+      return console.log("value not exist");
+    }
+  }
+
+  return console.log("Value not exists");
+}
+
+function printHashTable() {
+  console.log("==================");
+  for (let i = 0; i < hashTable.length; i++) {
+    console.log(`[${i}] ${hashTable[i]}`);
+  }
+}
+
+function main() {
+  const tokens = ["do", "for", "if", "case", "else", "return", "function"];
+
+  for (let i = 0; i < tokens.length; i++) {
+    const item = { key: tokens[i], value: tokens[i] };
+    addToHashTable(item);
+  }
+
+  printHashTable();
+}
+
+main();