思路：

1，利用左右指针的思想

2，因为至少要有两个数，所以最大值为：(1+sum) / 2;

3，指定起始序列为1，2

举个例子，sum=9的情况

 

 实现

void findContinuousSequence(int sum){
    if(sum < 3){
        return;
    }
    int small = 1;
    int big = 2;
    int mid = (1 + sum) >> 1;
    while (small < mid && big <= mid){
        int curSum = 0;
        for (int i = small; i <= big; ++i) {
            curSum += i;
        }
        if(curSum == sum){
            for (int i = small; i <= big; ++i) {
                if(i == big){
                    cout<<i<<"=";
                } else{
                    cout<<i<<"+";
                }
            }
            cout<<sum<<endl;
            big++;
        }
        else if(curSum < sum){// 序列小于指定值，big++
            big++;
        } else{
            small++;
        }
    }
}