前缀和的思想，两个for循环
public ArrayList<ArrayList<Integer>> FindContinuousSequence(int sum) {
ArrayList<ArrayList<Integer>> res = new ArrayList();
if(sum == 1 || sum == 0){
return res;
}
int numsLen = (int)(sum/2)+2;
int[] sums = new int[numsLen];
sums[0] = 0;
for(int i =1 ;i < numsLen;i++){
sums[i] = sums[i-1]+i;
}
for(int i =0 ;i < numsLen;i++){
for(int j= i+1;j < numsLen;j++){
if(sums[j]-sums[i] == sum){
ArrayList<Integer> temp = new ArrayList();
for(int k = i+1;k<=j;k++){
temp.add(k);
}
res.add(temp);
}
}
}
return res;
}
