240413 단어 공부

public static void main(String[] args) throws IOException {
	int[] arr = new int[26];

	int c = System.in.read();

	while (c > 64) {

		if (c < 91) {
			arr[c - 65]++;
		} else {
			arr[c - 97]++;
		}
		c = System.in.read();
	}

	int max = -1;
	int ch = 0;

	for (int i = 0; i < 26; i++) {

		if (arr[i] > max) {
			max = arr[i];
			ch = i;
		} else if (arr[i] == max) {
			ch = -2;
		}
	}
	System.out.print((char) (ch + 65));
}

출처:https://www.acmicpc.net/problem/1157