ABC - 115- A&B&C

AtCoder ABC 115 A&B&C

AtCoder - 115

A問題

	private static void ABC115_A() {
		Scanner scanner = null;
		int date = 0;

		try {
			scanner = new Scanner(System.in);
			date = scanner.nextInt();

			switch (date) {
			case 22:
				System.out.println("Christmas Eve Eve Eve");
				break;
			case 23:
				System.out.println("Christmas Eve Eve");
				break;
			case 24:
				System.out.println("Christmas Eve");
				break;
			case 25:
				System.out.println("Christmas");
				break;
			default:
				System.out.println("fail!");
				break;
			}

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}

B問題

• ソートして、一番最後（一番高い）ものを$1/2$にする

	private static void ABC115_B() {
		Scanner scanner = null;
		int numItem = 0;

		try {
			scanner = new Scanner(System.in);
			numItem = scanner.nextInt();
			int[] priceArray = new int[numItem];

			for (int i = 0; i < numItem; i++) {
				priceArray[i] = scanner.nextInt();
			}

			Arrays.sort(priceArray);

			int prices = 0;
			for (int i = 0; i < priceArray.length; i++) {
				if (i != numItem - 1) {
					prices += priceArray[i];
				} else {
					prices += priceArray[i] / 2;
				}

			}

			System.out.println(prices);

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}

C問題

• いくつか選択して飾り付けるので、選択する木は何でもよい
• 木を高さでソートして、N本連続で選択し、最小と最大を比較する
• N本連続するのを全てのパターン試せばよい

	private static void ABC115_C() {
		Scanner scanner = null;
		int totalTreeNum = 0;
		int selectedTreeNum = 0;

		try {
			scanner = new Scanner(System.in);
			totalTreeNum = scanner.nextInt();
			selectedTreeNum = scanner.nextInt();

			int[] treeTehightList = new int[totalTreeNum];

			for (int i = 0; i < totalTreeNum; i++) {
				treeTehightList[i] = scanner.nextInt();
			}

			Arrays.sort(treeTehightList);

			//			int[] sabunList = new int[treeTehightList.length - 1];

			//			for (int i = 0; i < sabunList.length; i++) {
			//				sabunList[i] = treeTehightList[i + 1] - treeTehightList[i];
			//			}
			int minDiff = 0;
			for (int i = 0; i < treeTehightList.length - (selectedTreeNum - 1); i++) {
				if (i == 0) {
					minDiff = treeTehightList[i + selectedTreeNum - 1] - treeTehightList[i];
				}
				if (minDiff > treeTehightList[i + selectedTreeNum - 1] - treeTehightList[i]) {
					minDiff = treeTehightList[i + selectedTreeNum - 1] - treeTehightList[i];
				}

			}
			System.out.println(minDiff);

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}