165th Commit

src/page-20/2103. Rings and Rods/countPoints.test.ts

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+import { countPoints } from './countPoints';
+
+describe('2103. Rings and Rods', () => {
+  test('countPoints', () => {
+    expect(countPoints('B0B6G0R6R0R6G9')).toBe(1);
+    expect(countPoints('B0R0G0R9R0B0G0')).toBe(1);
+    expect(countPoints('G4')).toBe(0);
+  });
+});

src/page-20/2103. Rings and Rods/countPoints.ts

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+type CountPoints = (rings: string) => number;
+
+/**
+ * Accepted
+ */
+export const countPoints: CountPoints = (rings) => {
+  // Initialize a Map to store rod colors
+  const rodColors = new Map<string, Set<string>>();
+
+  // Iterate through the rings string
+  for (let i = 0; i < rings.length; i += 2) {
+    const color = rings[i];
+    const rod = rings[i + 1];
+
+    // Add colors to the corresponding rod's set
+    rodColors.set(rod, (rodColors.get(rod) || new Set()).add(color));
+  }
+
+  // Count the rods with all three colors
+  let count = 0;
+
+  for (const [_, colors] of rodColors) {
+    if (colors.size === 3) count += 1;
+  }
+
+  return count;
+};