C++ 查找序列中的两个最大和最小整数_C++_If Statement_For Loop_Integer_Sequence

C++ 查找序列中的两个最大和最小整数

c++ if-statement for-loop

C++ 查找序列中的两个最大和最小整数,c++,if-statement,for-loop,integer,sequence,C++,If Statement,For Loop,Integer,Sequence,我试图在课堂上制作一个程序，在给定的序列中找出2个最大和最小的整数，然后将它们打印给用户。示例运行如下所示： Enter the sequence size: 8 Enter the sequence: 5 8 9 12 -6 4 -8 10 The two smallest values are: -8 -6 The two largest values are: 12 10 我不允许使用排序或数组。我整晚都在做这件事，但我似乎不明白，有人能给我指出正确的方向吗？这就是我目前所处的位置—

我试图在课堂上制作一个程序，在给定的序列中找出2个最大和最小的整数，然后将它们打印给用户。示例运行如下所示：

Enter the sequence size: 8
Enter the sequence: 5 8 9 12 -6 4 -8 10

The two smallest values are: -8 -6
The two largest values are: 12 10

我不允许使用排序或数组。我整晚都在做这件事，但我似乎不明白，有人能给我指出正确的方向吗？这就是我目前所处的位置——它不会编译，因为'small1'和'large1'变量没有初始化，但是如果我将它们设置为零，它们在示例运行中仍保持为零

int small1, small2, large1, large2, loopcount, sequencevalue;
// Ask the user to enter the first number
cout << "Sequence Size: ";
cin >> loopcount;

// Enter the sequence and start the loop
cout << "\nEnter the Sequence: ";

for (int i = 0; i < loopcount; i++)
{
    cin >> sequencevalue;

    if (sequencevalue < small1)
    {
        small2 = small1;
        small1 = sequencevalue;
    }

    if (sequencevalue > large1)
    {
        large2 = large1;
        large1 = sequencevalue;
    }
}

// Small variables
if (small1 == 0)
{
    small1 = sequencevalue;
}
else
{
    if (sequencevalue < small1)
    {
        small2 = small1;
        small1 = sequencevalue;
    }
}

// Large variables
if (large1 == 0)
{
    large1 = sequencevalue;
}
else
{
    if (sequencevalue < large1)
    {
        large2 = large1;
        large1 = sequencevalue;
    }
}

// Final Output
cout << "Two smallest values: " << small1 << " " << small2 << "\n";
cout << "Two largest values: " << large2<< " " << large1 << "\n";

int small1、small2、large1、large2、loopcount、sequencevalue；
//请用户输入第一个数字
cout>循环计数；
//输入序列并开始循环
cout>sequencevalue；
如果（sequencevaluelarge1）
{
大2=大1；
large1=序列值；
}
}
//小变量
if（small1==0）
{
small1=序列值；
}
其他的
{
如果（sequencevalue


注意这个程序的输出
#include <climits>
#include <iostream>

int main() {
    std::cout << INT_MAX << std::endl;
    std::cout << INT_MIN << std::endl;
    return 0;
}

#包括
#包括
int main（）{
std：：cout您正在寻找的

注意这个程序的输出
#include <climits>
#include <iostream>

int main() {
    std::cout << INT_MAX << std::endl;
    std::cout << INT_MIN << std::endl;
    return 0;
}

#包括
#包括
int main（）{
std:：cout您的程序具有未定义的行为，因为在初始化之前您正在使用small1
、small2
、large1
、large2

初始化small1
和small2
的正确方法是：
int small1 = INT_MAX;
int small2 = INT_MAX;

int large1 = INT_MIN;
int large2 = INT_MIN;

初始化large1
和large2
的正确方法是：
int small1 = INT_MAX;
int small2 = INT_MAX;

int large1 = INT_MIN;
int large2 = INT_MIN;

更新
在没有排序数组的情况下，正确更新数字的逻辑不是直接的。下面包含了一个工作程序，可以正确计算small1
和small2
。我将把它留给您扩展为计算large1
和large2

#include <iostream>
#include <sstream>
#include <climits>
#include <algorithm>

int main()
{
   std::istringstream str("8 5 8 9 12 -6 4 -8 10");

   int small1 = INT_MAX;
   int small2 = INT_MAX;

   int loopcount;
   bool small1_found = false;

   str >> loopcount;
   for (int i = 0; i < loopcount; ++i )
   {
      int sequencevalue;
      str >> sequencevalue;

      if ( sequencevalue < small1 )
      {
         int temp = small1;
         small1 = sequencevalue;
         if ( small1_found )
         {
            small2 = std::max(sequencevalue, temp);
         }
         small1_found = true;
      }

   }

   std::cout << "Two smallest values: " << small1 << " " << small2 << "\n";
}

您的程序具有未定义的行为，因为您在初始化它们之前正在使用small1
、small2
、large1
、large2

初始化small1
和small2
的正确方法是：
int small1 = INT_MAX;
int small2 = INT_MAX;

int large1 = INT_MIN;
int large2 = INT_MIN;

初始化large1
和large2
的正确方法是：
int small1 = INT_MAX;
int small2 = INT_MAX;

int large1 = INT_MIN;
int large2 = INT_MIN;

更新
在没有排序数组的情况下，正确更新数字的逻辑不是直接的。下面包含了一个工作程序，可以正确计算small1
和small2
。我将把它留给您扩展为计算large1
和large2

#include <iostream>
#include <sstream>
#include <climits>
#include <algorithm>

int main()
{
   std::istringstream str("8 5 8 9 12 -6 4 -8 10");

   int small1 = INT_MAX;
   int small2 = INT_MAX;

   int loopcount;
   bool small1_found = false;

   str >> loopcount;
   for (int i = 0; i < loopcount; ++i )
   {
      int sequencevalue;
      str >> sequencevalue;

      if ( sequencevalue < small1 )
      {
         int temp = small1;
         small1 = sequencevalue;
         if ( small1_found )
         {
            small2 = std::max(sequencevalue, temp);
         }
         small1_found = true;
      }

   }

   std::cout << "Two smallest values: " << small1 << " " << small2 << "\n";
}

我加入了climits并更正了你的代码
代码示例：
#include <iostream>
#include <climits>
using namespace std;

int main(){
    int count = 0;
    cout << "Sequence Size: ";
    cin >> count;

    int sequencevalue;

    int large1 = INT_MIN;
    int large2 = INT_MIN;
    int small1 = INT_MAX;
    int small2 = INT_MAX;

    for (int i = 0; i < count; i++){
        cin >> sequencevalue;
        if (sequencevalue >= large1) {
            large2 = large1;
            large1 = sequencevalue;
        }
        else if (sequencevalue > large2){
            large2 = sequencevalue;
        }
        if (sequencevalue <= small1) {
            small2 = small1;
            small1 = sequencevalue;
        }
        else if (sequencevalue < small2){
            small2 = sequencevalue;
        }
    }

    cout << "Sequence size is " << count << endl;
    if (0 == count) {}
    else if (1 == count){
        cout << "Smallest value: " << small1 << endl;
        cout << "Largest value: " << large1 << endl;
    }
    else{
        cout << "First and second smallest value: " << small1 << " " << small2 << endl;
        cout << "First and second largest value: " << large1 << " " << large2 << endl;
    }
    return 0;
}

#包括
#包括
使用名称空间std；
int main（）{
整数计数=0；
计数；
int序列值；
int large1=int_MIN；
int large2=int_MIN；
int small1=int_MAX；
int small2=int_MAX；
for（int i=0；i>序列值；
如果（sequencevalue>=large1）{
大2=大1；
large1=序列值；
}
否则如果（sequencevalue>large2）{
large2=序列值；
}
如果（sequencevalueI包含climits并更正了您的代码
代码示例：
#include <iostream>
#include <climits>
using namespace std;

int main(){
    int count = 0;
    cout << "Sequence Size: ";
    cin >> count;

    int sequencevalue;

    int large1 = INT_MIN;
    int large2 = INT_MIN;
    int small1 = INT_MAX;
    int small2 = INT_MAX;

    for (int i = 0; i < count; i++){
        cin >> sequencevalue;
        if (sequencevalue >= large1) {
            large2 = large1;
            large1 = sequencevalue;
        }
        else if (sequencevalue > large2){
            large2 = sequencevalue;
        }
        if (sequencevalue <= small1) {
            small2 = small1;
            small1 = sequencevalue;
        }
        else if (sequencevalue < small2){
            small2 = sequencevalue;
        }
    }

    cout << "Sequence size is " << count << endl;
    if (0 == count) {}
    else if (1 == count){
        cout << "Smallest value: " << small1 << endl;
        cout << "Largest value: " << large1 << endl;
    }
    else{
        cout << "First and second smallest value: " << small1 << " " << small2 << endl;
        cout << "First and second largest value: " << large1 << " " << large2 << endl;
    }
    return 0;
}

#包括
#包括
使用名称空间std；
int main（）{
整数计数=0；
计数；
int序列值；
int large1=int_MIN；
int large2=int_MIN；
int small1=int_MAX；
int small2=int_MAX；
for（int i=0；i>序列值；
如果（sequencevalue>=large1）{
大2=大1；
large1=序列值；
}
否则如果（sequencevalue>large2）{
large2=序列值；
}
if（sequencevalueint small1、small2、large1、large2、loopcount、sequencevalue；
//请用户输入第一个数字
cout>循环计数；
//输入序列并开始循环
cout>sequencevalue；
如果（i==0）
small1=序列值；
small2=序列值；
large2=序列值；
large1=序列值；}
如果（i==1）
{如果（sequencevalue>small1）small2=sequencevalue；
否则{
small2=small1；
small1=序列值；
}
大2=小1；
大1=小2；
}
如果（sequencevaluelarge1）
{
大2=大1；
large1=序列值；
}
}
//最终产量
coutint small1、small2、large1、large2、loopcount、sequencevalue；
//请用户输入第一个数字
cout>循环计数；
//输入序列并开始循环
cout>sequencevalue；
如果（i==0）
small1=序列值；
small2=序列值；
large2=序列值；
large1=序列值；}
如果（i==1）
{如果（sequencevalue>small1）small2=sequencevalue；
否则{
small2=small1；
small1=序列值；
}
大2=小1；
大1=小2；
}
如果（sequencevaluelarge1）
{
大2=大1；
large1=序列值；
}
}
//最终产量
给你
#include <iostream>

int main() 
{
    while ( true )
    {
        // Ask the user to enter the first number
        std::cout << "Sequence Size: ";

        unsigned int loopcount;

        if ( not ( std::cin >> loopcount ) || ( loopcount == 0 ) ) break; 

        int small1, small2, large1, large2;

        // Enter the sequence and start the loop
        std::cout << "\nEnter the Sequence: ";

        unsigned int i = 0;

        for ( ; i < loopcount; i++ )
        {
            int sequencevalue;

            std::cin >> sequencevalue;

            if ( i == 0 )
            {
                small1 = sequencevalue;
                large1 = sequencevalue;
            }
            else
            {
                if ( large1 < sequencevalue )
                {
                    large2 = large1;
                    large1 = sequencevalue;
                }
                else if ( i == 1 || large2 < sequencevalue )
                {
                    large2 = sequencevalue;
                }

                if ( sequencevalue < small1 )
                {
                    small2 = small1;
                    small1 = sequencevalue;
                }
                else if ( i == 1 || sequencevalue < small2 )
                {
                    small2 = sequencevalue;
                }
            }
        }

        if ( i == 1 )
        {
            printf( "There is only one largest value %d\n",
                large1 );
            printf( "And only one mallest value %d\n",
                small1 );
        }
        else
        {
            printf( "The first largest value is %d and the second largest value is %d\n",
                large1, large2 );

            printf( "And the first smallest value is %d and the second smallest value is %d\n",
                small1, small2 );
        }

    }

    return 0;
}

给你
#include <iostream>

int main() 
{
    while ( true )
    {
        // Ask the user to enter the first number
        std::cout << "Sequence Size: ";

        unsigned int loopcount;

        if ( not ( std::cin >> loopcount ) || ( loopcount == 0 ) ) break; 

        int small1, small2, large1, large2;

        // Enter the sequence and start the loop
        std::cout << "\nEnter the Sequence: ";

        unsigned int i = 0;

        for ( ; i < loopcount; i++ )
        {
            int sequencevalue;

            std::cin >> sequencevalue;

            if ( i == 0 )
            {
                small1 = sequencevalue;
                large1 = sequencevalue;
            }
            else
            {
                if ( large1 < sequencevalue )
                {
                    large2 = large1;
                    large1 = sequencevalue;
                }
                else if ( i == 1 || large2 < sequencevalue )
                {
                    large2 = sequencevalue;
                }

                if ( sequencevalue < small1 )
                {
                    small2 = small1;
                    small1 = sequencevalue;
                }
                else if ( i == 1 || sequencevalue < small2 )
                {
                    small2 = sequencevalue;
                }
            }
        }

        if ( i == 1 )
        {
            printf( "There is only one largest value %d\n",
                large1 );
            printf( "And only one mallest value %d\n",
                small1 );
        }
        else
        {
            printf( "The first largest value is %d and the second largest value is %d\n",
                large1, large2 );

            printf( "And the first smallest value is %d and the second smallest value is %d\n",
                small1, small2 );
        }

    }

    return 0;
}

也许把值设置为0是错误的值？你会建议我初始化它们吗？从我理解的C++中的任何变量都有一个值，包括NULL，它只是0。在C++中，正确的初始化<代码> SLM1将是<代码> STD::NoimiCiLime::Max（）。也许将这些值设置为0是错误的值吗？你会建议我如何初始化它们？从我理解的，C++中的任何变量都有一个值，包括NULL，它只是0。C++中，正确的初始化代码< Simult1< /代码