r,e,d三个字符,能否构成含有 cnt 个回文串的字符串 s原理:n个相同的字符构建的回文子串的个数为n(n+1)/2,其余的用edr补```public static void deal1() {Scanner sc = new Scanner(System.in);int x = sc.nextInt();int n = (int) (Math.sqrt(2*x + 0.25) - 0.5);StringBuilder sb = new StringBuilder();for (int i = 0; i < n; i++) {sb.append("r");}n = n * (n+1) / 2;int y = (x - n) / 3;for (int i = 0; i < y; i++) {sb.append("edr");}if (n + y * 3 == x) {System.out.println(sb);} else if (n + y * 3 + 1 == x) {sb.append("e");System.out.println(sb);} else if (n + y * 3 + 2 == x) {sb.append("ed");System.out.println(sb);}```