字符串匹配-暴力匹配算法

package com.william_wei.interview.other;

/**
 * @Describe
 * @Author: william_xhw
 * @Version 1.0
 */
public class MatchStringJava {

    private Integer base = 0;

    private String str_s;

    private String str_t;

    public MatchStringJava(String str_s, String str_t) {
        this.str_s = str_s;
        this.str_t = str_t;
    }


    public Integer run() {

        int sourceLength = str_s.length();
        int targetLength = str_t.length();

        // 长度匹配
        while (base + targetLength <= sourceLength) {
            int step = 0;
            while (step < targetLength) {
                //目标串的步长位置值  与  源字符串对应位置 比较
                if (str_t.charAt(step) == str_s.charAt(base + step)) {
                    step += 1;
                    continue;
                }
                //如果不匹配，基准位置递增1
                base += 1;
                break;
            }
            //步长是否等于目标字符串的长度.
            if (step == targetLength) {
                return base;
            }
        }
        return -1;
    }

    public static void main(String[] args) {

        System.out.println(new MatchStringJava("badfsdfd", "sdf").run());

        //输出结果为4

    }
}