新手

flag标记

#include <iostream>
using namespace std;
#include <string.h>
#include <math.h>

int main ()
{
	int n;
	while (	cin >> n)
	{
		int s[n];
		for (int i = 0; i < n; i++)
			cin >> s[i];
		int flag = 0;
		int a = 0;
		int b = 0;
		int height = 0;
		for (int i = 0; i < n - 1; i++)
		{
			if (s[i+1] > s[i] && flag == 0)//后一个比前一个大，递增序列开始，返回前一个较小数字给a
			{
				flag = 1;
				a = s[i]; 
//				cout << "a = " << a << endl;
			}
			if (s[i+1] < s[i] && flag == 1)//后一个比前一个小，递增序列结束,返回前一个较大的数给b
			{
				flag = 0;
				b = s[i];
//				cout << "b = " << b << endl;
				height = max( b-a, height);//比较
			}
			if ((i + 1) == (n -1) && s[i+1] > s[i] && flag == 1)//如果遍历到末尾时依旧是递增序列，直接返                      
			{                                                   //回最后一个数给b
				b = s[i+1];
//				cout << "b = " << b << endl;
				h...