永無鄉
阿新 • • 發佈：2021-10-10
給定兩個字串str1和str2,輸出兩個字串的最長公共子串，如果最長公共子串為空，輸出-1。
心之所向，素履以往 生如逆旅，一葦以航import java.util.Scanner; public class Main { private static String solve(String str1, String str2) { int maxLenght = 0, maxIndex = 0; int row = 0, col = str2.length() - 1; while (row < str1.length() && col >= 0) { int dp = 0; int x = row, y = col; while (x < str1.length() && y < str2.length()) { dp = str1.charAt(x) == str2.charAt(y) ? dp + 1 : 0; if (dp > maxLenght) { maxLenght = dp; maxIndex = x; } x++; y++; } if (col > 0) { col--; } else { row++; } } return maxLenght == 0 ? "-1" : str1.substring(maxIndex - maxLenght + 1, maxIndex + 1); } public static void main(String[] args) { Scanner in = new Scanner(System.in); while (in.hasNext()) { System.out.println(solve(in.next(), in.next())); } } }