d3: initial sub

2022/d3/src/d3_deno.ts

@@ -4,3 +4,29 @@ if(Deno.args.length < 1) {
 const fileLoc = Deno.args[0];
 const text = await Deno.readTextFile(fileLoc);
 
+// Usable by Windows and UNIX
+const LINE_SPLIT = (/\r?\n/);
+
+function priority(chr: string) {
+    if(chr.length != 1) {
+        throw Error("Expecting character");
+    }
+
+    const ord = (v: string) => v.charCodeAt(0);
+    return (ord('a') <= ord(chr) && ord(chr) <= ord('z'))? (ord(chr) - ord('a') + 1):
+        (ord(chr) - ord('A') + 1);
+}
+
+const sumPrioOfShared = text.split(LINE_SPLIT) // split by each line, basically iterates through each rucksack
+    .map(s=>[...s].map(priority)) // translate each character into respective priority
+    .map((v)=> [v.slice(0, v.length/2), v.slice(v.length/2, v.length) ]) // splits by 2 compartments
+    .map(([left, right])=> {
+        // Finds the value on the right compartment that also exists in left compartment
+        const left_set = new Set(left);
+        // by the prompt, we're pretty guaranteed to have a solution
+        const shared =  right.find(e => left_set.has(e))!;
+        console.log("shared:", shared);
+        return shared;
+    }).reduce((a,b)=>a+b); // find its sum
+
+console.log(sumPrioOfShared);