package com.company;

import org.junit.Test;

import java.util.ArrayList;

public class FindContinuousSequence {

public ArrayList<ArrayList<Integer>> FindContinuousSequence(int sum) {

ArrayList<ArrayList<Integer>> mArrayLists = new ArrayList<>();

// 高位指针和低位指针

int pLow = 1;

int pHigh = 2;

// 终止条件是pHigh等于sum

while (pHigh > pLow) {

// 当前和，使用求和公式s = (a+b) * n / 2

int curSum = (pLow + pHigh) * (pHigh - pLow + 1) >> 1;

if (curSum < sum) pHigh++;

if (curSum == sum) {

ArrayList<Integer> temp = new ArrayList<>();

for (int i = pLow; i <= pHigh; i++) {

temp.add(i);

}

mArrayLists.add(temp);

pLow++;

}

if (curSum > sum) {

pLow++;

}

}

return mArrayLists;

}

@Test

public void test() {

FindContinuousSequence(100);

}

}