Next Greater Element I

最新推荐文章于 2021-10-26 01:11:44 发布

deepeed121

最新推荐文章于 2021-10-26 01:11:44 发布

阅读量235

点赞数

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/hk121/article/details/78301253

本文介绍了一个C++实现的问题解决方法，旨在寻找数组中每个元素的下一个更大的元素，并通过调试修正了输出和函数返回类型等问题。

It is the first that I have solved a problem without baidu the answer.

problem: You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset ofnums2. Find all the next greater numbers for nums1's elements in the corresponding places ofnums2.

The Next Greater Number of a number x in nums1 is the first greater number to its right innums2. If it does not exist, output -1 for this number.

1,错误一：输出是vector不是一个数

2，错误二：return -1 和return nums[t]不对，

vector<int> nextGreaterElement(vector<int>& findNums, vector<int>& nums) {返回的是一个整形vector

改成int nextGreaterElement(vector<int>& findNums, vector<int>& nums)

3，break位置要调式得知】

4，vector赋初值：http://www.cnblogs.com/gtt1025/p/5859585.html

#include<iostream>
#include<string>
#include<vector>
using namespace std;

vector<int> nextGreaterElement(vector<int>& findNums, vector<int>& nums) {
	vector<int> rect;
	for (int i = 0; i<findNums.size(); i++)
	{
		for (int j = 0; j<nums.size(); j++)
		{
			if (findNums[i] == nums[j])
			{
				for (int t = j; t<nums.size(); t++)
				{
					if (findNums[i] < nums[t])
					{
						rect.push_back(nums[t]);
						break;
					}
					if (t == nums.size() - 1)
						rect.push_back(-1);
				}
				
			}

		}

	}
	return rect;
};

int main()
{
	vector<int> ilist, ilist2;
	ilist.push_back(1);
	ilist.push_back(3);
	ilist.push_back(4);
	ilist.push_back(2);

	ilist2.push_back(4);
	ilist2.push_back(1);
	ilist2.push_back(2);
	nextGreaterElement(ilist2, ilist);
}

这种只能调试，不能输出vector结果，查vector输出：http://blog.youkuaiyun.com/lovemysea/article/details/5303897

return rect;
   for (std::vector<int>::iterator m = rect.begin(); m != rect.end(); m++)    //用迭代器的方式输出容器对象的值
   {
       cout << *m << endl;
   }

这样没错，就是输出不了，过了return rect;后rect就空了；

原来return rect要放在最后；

完整代码：

#include<iostream>
#include<string>
#include<vector>
using namespace std;


  
vector<int> nextGreaterElement(vector<int>& findNums, vector<int>& nums) {
	vector<int> rect;
	for (int i = 0; i<findNums.size(); i++)
	{
		for (int j = 0; j<nums.size(); j++)
		{
			if (findNums[i] == nums[j])
			{
				for (int t = j; t<nums.size(); t++)
				{
					if (findNums[i] < nums[t])
					{
						rect.push_back(nums[t]);
						break;
					}
					if (t == nums.size() - 1)
						rect.push_back(-1);
				}
				
			}

		}
	}
	for (std::vector<int>::iterator m = rect.begin(); m != rect.end(); m++)    //用迭代器的方式输出容器对象的值
	{
		cout << *m << endl;
	}
	return rect;
};

int main()
{
	
	vector<int> ilist, ilist2;
	ilist.push_back(1);
	ilist.push_back(3);
	ilist.push_back(4);
	ilist.push_back(2);

	ilist2.push_back(4);
	ilist2.push_back(1);
	ilist2.push_back(2);
	nextGreaterElement(ilist2, ilist);

}

结果：

第二部实施改写，printf输出

代码：

#include<iostream>
#include<string>
#include<vector>
using namespace std;

int nextGreaterElement(vector<int>& findNums, vector<int>& nums) {
	for (int i = 0; i<findNums.size(); i++)
	{
		for (int j = 0; j<nums.size(); j++)
		{
			if (findNums[i] == nums[j])
			{
				for (int t = j; t<nums.size(); t++)
				{
					if (findNums[i] < nums[t])
					{
						printf( "%d\n", nums[t] );
						break;
					}
					if (t == nums.size() - 1)
						printf("%d\n", -1);
				}
				
			}

		}

	}
	return 90;
};

int main()
{
	vector<int> ilist, ilist2;
	ilist.push_back(1);
	ilist.push_back(3);
	ilist.push_back(4);
	ilist.push_back(2);

	ilist2.push_back(4);
	ilist2.push_back(1);
	ilist2.push_back(2);
	nextGreaterElement(ilist2, ilist);
}

结果：