在数组中查找最小值
在数组中查找最小值
提问于 2014-10-02 17:36:34
我有两个数组：
int playerSums[9] = { };
string playerNames[9] = { };我正在尝试获取数组中的最小值，以及该值的数组索引。
到目前为止，我尝试过的是：
if (playerNames[index] == "End" || playerNames[index] == "end") {
int lowestValue = playerSums[0];
for (i = 1; i < sizeof(playerSums) / sizeof(playerSums[0]); i++) {
if (playerSums[i] < lowestValue || lowestValue != 0)
lowestValue = playerSums[i];
}
cout << index[playerNames] << " had the lowest values and got the sum ";
cout << lowestValue << endl;
}如何在数组playerSums中找到和显示最小值(例如，只播放3名播放器，即只填充数组的3个元素(其余元素等于0)？
我需要索引来显示得到最小值的球员的名字。
回答 5
Stack Overflow用户
回答已采纳
发布于 2014-10-02 17:53:08
您可以使用标头std::min_element中声明的标准算法<algorithm>来用最小和查找元素。例如
#include <algorithm>
int *min = std::min_element( playerSums, playerSums + 3 );
std::cout << playerNames[min - playerSums]
<< " had the lowest values and got the sum " << *min
<< std::endl;也可以使用标头中声明的标准函数std::begin、std::end和std::distance编写。
#include <algorithm>
#include <iterator>
int *min = std::min_element( std::begin( playerSums ), std::end( playerSums ) );
std::cout << playerNames[ std::distance( playerSums, min )]
<< " had the lowest values and got the sum " << *min
<< std::endl;您可以编写类似于该算法的函数，而不是使用该算法。例如
size_t min_sum( const int playerSums[], size_t n )
{
size_t min = 0;
for ( size_t i = 1; i < n; i++ )
{
if ( playerSums[min] < playerSums[i] ) min = i;
}
return min;
}
size_t min = min_sum( playerSums, sizeof( playerSums ) / sizeof( *playerSums ) );
std::cout << playerNames[min]
<< " had the lowest values and got the sum " << playerSums[min]
<< std::endl;如果需要跳过等于零的数组元素，则该函数如下所示
size_t min_sum( const int playerSums[], size_t n )
{
size_t min = 0;
while ( min < n && playerSums[i] == 0 ) ++min;
for ( size_t i = min; i < n; i++ )
{
if ( playerSums[min] < playerSums[i] ) min = i;
}
return min;
}
size_t min = min_sum( playerSums, sizeof( playerSums ) / sizeof( *playerSums ) );
if ( min != sizeof( playerSums ) / sizeof( *playerSums ) )
{
std::cout << playerNames[min]
<< " had the lowest values and got the sum " << playerSums[min]
<< std::endl;
}Stack Overflow用户
发布于 2014-10-02 17:53:21
就像在lowestValue中存储最低值一样，将索引存储在变量中，比方说，lowestValueIndex。另外，移除外部if并将其移动到for循环中：
if(playerNames[i] == "End" || playerNames[i] == "end")
break;这样，您将确保只有正在比赛的球员将被处理。另外，您将不再需要检查最低值是否为零。因此，代码看起来如下：
int lowestValue = playerSums[0];
int lowestValueIndex = 0;
for (int i = 1; i < sizeof(playerSums)/sizeof(playerSums[0]); ++i)
{
if(playerNames[i] == "End" || playerNames[i] == "end")
break;
if (playerSums[i] < lowestValue)
{
lowestValue = playerSums[i];
lowestValueIndex = i;
}
}
cout << index[playerNames] << " had the lowest values and got the sum "
<< lowestValue << endl;请注意，使用可以增长的标准数组来简化这一点(如vector)：
std::vector<std::string> playerNames;
std::vector<int> playerSums;
for (int i = 1; i < playerSums.size(); ++i)
{
if (playerSums[i] < lowestValue)
{
lowestValue = playerSums[i];
lowestValueIndex = i;
}
}
cout << index[playerNames] << " had the lowest values and got the sum "
<< lowestValue << endl;Stack Overflow用户
发布于 2014-10-02 17:53:38
和往常一样，最简单的解决方案是使用标准库。
auto it = std::min_element(std::begin(playerSums), std::end(playerSums));
std::size_t index = std::distance(std::begin(playerSums), it);现在，您可以通过取消迭代器it来获得min值。
int lowestValue = *it;如果只想迭代数组中的前3个元素，那么可以这样做：
auto first = std::begin(playerSums);
auto it = std::min_element(first, std::next(first, 3));
std::size_t index = std::distance(first, it);注意:喜欢std::next而不是普通指针算法(例如，playerSums + 3)，因为它更通用(适用于所有迭代器类型)。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/26166337
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