C++：出现在输出中的奇怪数字

Question

对于我的学校项目，我应该用大约-10和10之间的随机数填充20的数组。然后，我必须根据它们是否为负值来组织这些数字，0或正数。我被告知要完成打印出原始数组的程序，以及新的数组。

出于某种原因，有组织的数组在某些空格中打印出随机（TYPE：long）数字。我不确定为什么会出现这种情况。下面是我的代码：

#include <iostream> 
#include <stdlib.h> 
#include <time.h> 

int main(int argc, const char * argv[]) { 
// insert code here... 
srand(time(NULL)); 
int numbers[20], final[20], first = 1, second = 1; 

std::cout << "Enter 20 numbers, and without sorting, this program will take them and organize them based on positive, negative, and 0.\n\n"; 
for(int i = 0; i < 20; i++){ 
    std::cout << "Enter number " << (i+1) << ": "; 
    //std::cin >> numbers[i]; 
    numbers[i] = (rand()%20 -10); 
    std::cout << numbers[i] << std::endl; 
} 

//Numbers lower than 0 
for(int i = 0; i < 20; i++){ 
    if(numbers[i] < 0){ 
     final[i] = numbers[i]; 
     first++; 
    } 
} 
//Numbers equal to 0 
for(int i = first; i < 20; i++){ 
    if(numbers[i] == 0){ 
     final[i] = numbers[i]; 
     second++; 
    } 
} 
//Numbers greater than 0 
for(int i = second; i < 20; i++){ 
    if(numbers[i] == 0){ 
     final[i] = numbers[i]; 
    } 
} 

std::cout << "This is your original array: "; 
for(int i = 0; i < 20; i++){ 
    std::cout << numbers[i]; 
    if(i != 19) 
     std::cout << ","; 
    std::cout << " "; 
    if(i == 19) 
     std::cout << std::endl << std::endl << std::endl; 
} 

std::cout << "This your new, organized, array: "; 
for(int i = 0; i < 20; i++){ 
    std::cout << final[i]; 
    if(i != 19) 
     std::cout << ","; 
    std::cout << " "; 
    if(i == 19) 
     std::cout << std::endl << std::endl << std::endl; 
} 

system("pause"); 
return 0; 
} 

我的输出是这样的：

Enter 20 numbers, and without sorting, this program will take them and organize them based on positive, negative, and 0. 

Enter number 1: -6 
Enter number 2: 0 
Enter number 3: -4 
Enter number 4: -5 
Enter number 5: 0 
Enter number 6: -4 
Enter number 7: -5 
Enter number 8: -5 
Enter number 9: -8 
Enter number 10: 5 
Enter number 11: 0 
Enter number 12: -3 
Enter number 13: 5 
Enter number 14: -5 
Enter number 15: 7 
Enter number 16: 2 
Enter number 17: 9 
Enter number 18: 9 
Enter number 19: 3 
Enter number 20: 2 
This is your original array: -6, 0, -4, -5, 0, -4, -5, -5, -8, 5, 0, -3, 5, -5, 7, 2, 9, 9, 3, 2 


This your new, organized, array: -6, 1879110449, -4, -5, 0, -4, -5, -5, -8, 1, 0, -3, 1606416384, -5, 1606423158, 32767, 1606416416, 32767, 1606416416, 32767" 

预先感谢您所有谁答复。对此，我真的非常感激。

Answer 1

你是不是把在正确的final阵列位置的数量，检查有现在first被用来标明在下一元素应该放在最后一个数组的位置：

而且我删除未使用的second变量

#include <iostream> 
#include <stdlib.h> 
#include <time.h> 

int main(int argc, const char * argv[]) { 
// insert code here... 
srand(time(NULL)); 
// changed first = 1 to first = 0 and eliminated second 
int numbers[20], final[20], first = 0; 

std::cout << "Enter 20 numbers, and without sorting, this program will take them and organize them based on positive, negative, and 0.\n\n"; 
for(int i = 0; i < 20; i++){ 
    std::cout << "Enter number " << (i+1) << ": "; 
    //std::cin >> numbers[i]; 
    numbers[i] = (rand()%20 -10); 
    std::cout << numbers[i] << std::endl; 
} 

//Numbers lower than 0 
for(int i = 0; i < 20; i++){ 
    if(numbers[i] < 0){ 
     // now it is put in final[first] instead of final[i] 
     final[first] = numbers[i]; 
     first++; 
    } 
} 
//Numbers equal to 0 
//changed i to start from 0 again 
for(int i = 0; i < 20; i++){ 
    if(numbers[i] == 0){ 
     final[first] = numbers[i]; 
     first++; 
    } 
} 
//Numbers greater than 0 
for(int i = 0; i < 20; i++){ 
    if(numbers[i] > 0){ // Yeah, here was the typo... replaced `==` with `>` 
     final[first] = numbers[i]; 
     // added this increment 
     first++; 
    } 
} 

std::cout << "This is your original array: "; 
for(int i = 0; i < 20; i++){ 
    std::cout << numbers[i]; 
    if(i != 19) 
     std::cout << ","; 
    std::cout << " "; 
    if(i == 19) 
     std::cout << std::endl << std::endl << std::endl; 
} 

std::cout << "This your new, organized, array: "; 
for(int i = 0; i < 20; i++){ 
    std::cout << final[i]; 
    if(i != 19) 
     std::cout << ","; 
    std::cout << " "; 
    if(i == 19) 
     std::cout << std::endl << std::endl << std::endl; 
} 

system("pause"); 
return 0; 
} 

Answer 2

对于numbers阵列，final阵列的索引器应该从索引器（i）中独立增加。换句话说：

int idxFinal = 0; // determines where on the 'array' index to insert next 

for(int i = first; i < 20; i++){ 
    if(numbers[i] < 0){ 
     final[idxFinal] = numbers[i]; 
     first++; 
     idxFinal++; 
    } 
} 

... 

//Numbers equal to 0 
for(int i = first; i < 20; i++){ 
    if(numbers[i] == 0){ 
     final[idxFinal++] = numbers[i]; 
     second++; 
    } 
} 

的另一个问题与您的代码是一款//Numbers greater than 0内的if声明一个错字。我会让你的身影，一个为自己:)

Answer 3

你的输出越来越陌生号码，因为您的代码不完全填充阵列（它打印出那些已经对这些存储位置的内容）。

，不会产生代码（你几乎没有）：

• 你应该通过整个数组的大小（0〜20）的迭代循环for（他们三个），请记住，在这些你试图检查值的循环，所以你需要经历所有的值。
• 根据您的计数器（first,second），而不是基于i，分配给您的最终阵列。再次，i只是用来遍历数组。这会导致您的阵列在这里出现漏洞。当您输入if报表并且仅在其各自的职位（i）中时，您只将值分配给final。
• 您的if对于数字大于零的语句不正确，它会检查是否等于。
• 初始化first和second 0，而不是1

应该这样做。作为一个方面说明，你并不需要两个单独的计数器，first和second。你可以只使用一个，在你的第一个循环中增加它，然后在第二个循环中继续增加它，等等。