字符串统计，例如输入"aaabbffff"返回"a3b2f4"

package demo;

public class P73 {
//字符串统计，例如输入"aaabbffff"返回"a3b2f4"
	public static void main(String[] args) {
		String src = "aaabbffff";
		StringBuilder result = countString(src);
		System.out.println(result);
	}

	static StringBuilder countString(String src) {
		char last = src.charAt(0);		//记录上一个字符
		int count = 1;					//记录重复次数
		char charAt;
		StringBuilder sb = new StringBuilder();

		for (int i = 1; i < src.length(); i++) {
			charAt=src.charAt(i);
			if(last==charAt) {
				count++;
			}
			else {
				sb.append(last).append(count);
				last=charAt;
				count=1;
			}
		}
		sb.append(last).append(count);
		return sb;
	}

}