c++模板

1. 问题描述

分别找出一组int型数据,一组double型数据，一组字符数组型数据的最大值并输出。main函数代码如下所示：

int main()
{
	int a[] = { 5,4,6,2,0,12,8,7,1,3 };
	double b[] = { 1.1,3.3,5.5,6.6,4.4,7.7,9.9,8.8,0.0,2.2 };
	const char* c[] = { "Huaian","Yancheng","Yangzhou","Nanjing","Suzhou" };
	cout << max<int>(a, sizeof(a) / sizeof(int)) << endl;
	cout << max<double>(b, sizeof(b) / sizeof(double)) << endl;
	cout << max(c, 5) << endl;//调用char* max(const char* a[], int n)
	return 0;
}

2、分析

double型数据与int型数据考虑用模板写，字符数组单独定义一个函数供其调用。

3、代码实现

#include<iostream>
#include<cstring>
using namespace std;
template<class	T>//模板
T max(T a[], int n)
{
	T m = a[0];
	for (int i = 1; i < n; i++)
	{
		if (a[i] > m)
		{
			m = a[i];
		}
	}
	return m;
}
char* max(const char* a[], int n)
{
	char* str = new char[50];
	strcpy_s(str, strlen(a[0]) + 1, a[0]);
	for (int i = 1; i < n; i++)
	{
		if (strcmp(a[i], str) > 0)
		{
			strcpy_s(str, strlen(a[i]) + 1, a[i]);
		}
	}
	return str;
}
int main()
{
	int a[] = { 5,4,6,2,0,12,8,7,1,3 };
	double b[] = { 1.1,3.3,5.5,6.6,4.4,7.7,9.9,8.8,0.0,2.2 };
	const char* c[] = { "Huaian","Yancheng","Yangzhou","Nanjing","Suzhou" };
	cout << max<int>(a, sizeof(a) / sizeof(int)) << endl;
	cout << max<double>(b, sizeof(b) / sizeof(double)) << endl;
	cout << max(c, 5) << endl;//调用char* max(const char* a[], int n)
	return 0;
}