合并连续数字的算法

public class Test {
public static void main(String[] args) {
String str = new String(
"1,2,3,4,5,6,7,8,9,11,13,14,1000,1001,1002,1003");
String[] s = str.split(",");
int[] num = new int[s.length];
String result = "";
for (int i = 0; i < s.length; i++) {
num[i] = Integer.parseInt(s[i]);
}
for (int i = 0; i < num.length; i++) {
if (i == 0) {
result = "" + num[i];
} else if (i == num.length - 1) {
if (num[i] - num[i - 1] == 1) {
result = result + "-" + num[i];
} else {
result = result + "," + num[i];
}
} else {
if ((num[i] - num[i - 1] == 1) && (num[i + 1] - num[i] == 1)) {
continue;
}
if ((num[i] - num[i - 1] == 1) && (num[i + 1] - num[i] != 1)) {
result = result + "-" + num[i];
}
if ((num[i] - num[i - 1] != 1)) {
result = result + "," + num[i];
}

}

}
System.out.println(result);
}
}