LCS算法实现 求两个字符串中间最长的公共子串

package util;import java.util.ArrayList;import java.util.List;/** * LCS算法实现 求两个字符串中间最长的公共子串 * @author landing * */public class LCSImpl {public int getSameStr(String str1,String str2){char[] arrchar1 = str1.toCharArray();char[] arrchar2 = str2.toCharArray();int[][]
arr = new int[arrchar1.length][arrchar2.length];int len = arrchar1.length < arrchar2.length ? arrchar1.length : arrchar2.length;int maxarr[] = new int[len];int maxindex[] = new int[len];for(int i = 0; i<arrchar1.length; i++){for(int j = 0; j<arrchar2.length;
j++){if (arrchar2[j] == arrchar1[i]) {if (i == 0 || j == 0) {arr[i][j] = 1;if (maxarr[0] < 1) {maxarr[0] = 1;maxindex[0] = i;}} else {arr[i][j] = arr[i - 1][j - 1] + 1;// 如果当前求出的子串长度大于了maxarr中第一个数值 则清空maxarr数值 全部置0// 同时替换第一个最大值if (maxarr[0] < arr[i][j]) {maxarr[0]
= arr[i][j];maxindex[0] = i;for (int num = 1; num < maxarr.length; num++) {if (maxarr[num] == 0) {break;} else {maxarr[num] = 0;maxindex[num] = 0;}}} else if (maxarr[0] == arr[i][j]) {// 如果当前求出的子串长度跟maxarr中第一个一致 则保留int num = 0;for (int max : maxarr) {if (max
== 0) {maxarr[num] = arr[i][j];maxindex[num] = i;break;}num++;}}}} else {arr[i][j] = 0;}}}List list = new ArrayList();int longLength = 0;for (int i = 0; i < maxarr.length; i++) {if (maxarr[i] == 0) {break;}int num = maxindex[i] - (maxarr[i] - 1);String str
= "";for (int k = 0; k < maxarr[i]; k++) {char tempchar = arrchar1[num];str += String.valueOf(tempchar);num++;}// System.out.println(str);// System.out.println(str.length());list.add(str);}int temp = 0;for (int i = 0; i < list.size(); ++i) {temp = list.get(i).length();if
(temp > longLength) {longLength = temp;}}return longLength;}/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stub}}