用JAVA写一个函数。功能例如以下：随意给定一组数，比如{12,60,-8,99,15,35,17,18},找出随意数相加之后的结果为35(随意设定)的情况.
能够递归算法来解:
package test1;
import java.util.Arrays;
public class demo {
public static void main(String[] args) {
String str = "12,60,-8,99,15,35,17,18,8,10,11,12";
int sum = 35;
diguiSum(str,sum);
}
public static void diguiSum(String str,int sum) {
String[] x = str.split(",");
int[] array = arrayTransform(x);
for (int i = 0; i < array.length; i++) {
int[] cache = new int[i + 1];
int ceng = -1;
int cengQuit = i;
int startPiont = 0;
cir(ceng, cengQuit, startPiont, array, cache, sum);
}
}
// 递归求结果
public static void cir(int ceng, int cengQuit, int startPiont, int[] array, int[] cache, int sum) {
ceng++;
for (int i = startPiont; i < array.length; i++) {
cache[ceng] = array[i];
if (ceng == cengQuit) {
if (getSum(cache) == sum) {
printcache(cache);
}
if (getSum(cache) > sum) {
break;
}
}
if (ceng < cengQuit) {
startPiont = i + 1;
cir(ceng, cengQuit, startPiont, array, cache,sum);
}
}
}
// 获取组合数字之和
public static int getSum(int[] cache) {
int sum = 0;
for (int i = 0; i < cache.length; i++) {
sum = sum + cache[i];
}
return sum;
}
// 打印组合的可能
public static void printcache(int[] cache) {
for (int i = 0; i < cache.length; i++) {
System.out.print(cache[i] + ",");
}
System.out.println();
}
// 转换数组类型 且为提高效率做准备
public static int[] arrayTransform(String[] strArray) {
int length = 0;
int[] array = new int[strArray.length];
for (int i = 0; i < strArray.length; i++) {
array[i] = Integer.valueOf(strArray[i]);
}
Arrays.sort(array);
for (int i = 0; i < array.length; i++) {
if (array[i] > 35) {
length = i;
break;
}
}
int[] dest = new int[length];
System.arraycopy(array, 0, dest, 0, length);
return dest;
}
}
此算法有做适当參考。
执行结果：