Recursion.
/**
* sum from 1 to n. recursion
* @param i
* @return sum
*/
public int recur_head(int i){
System.out.println("i = "+ i);
if(i==1)
return 1;
else
return i+recur_head(i-1);
}
tail Recursion.
/***
* sum from 1 to n. tail recursion
* @param i
* @param total
* @return
*/
public int recur_tail(int i, int total){
System.out.println("i = "+ i+", total = "+ total);
if (i == 1)
return 1+total;
return recur_tail(i-1, total +i);
}
原文：http://my.oschina.net/u/1767744/blog/305910