C++：出現在輸出中的奇怪數字

Question

對於我的學校項目，我應該用大約-10和10之間的隨機數填充20的數組。然後，我必須根據它們是否爲負值來組織這些數字，0或正數。我被告知要完成打印出原始數組的程序，以及新的數組。

出於某種原因，有組織的數組在某些空格中打印出隨機（TYPE：long）數字。我不確定爲什麼會出現這種情況。下面是我的代碼：

#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; 
} 

我的輸出是這樣的：

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" 

預先感謝您所有誰答覆。對此，我真的非常感激。

Answer 1

你是不是把在正確的final陣列位置的數量，檢查有現在first被用來標明在下一元素應該放在最後一個數組的位置：

而且我刪除未使用的second變量

#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

對於numbers陣列，final陣列的索引器應該從索引器（i）中獨立增加。換句話說：

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++; 
    } 
} 

的另一個問題與您的代碼是一款//Numbers greater than 0內的if聲明一個錯字。我會讓你的身影，一個爲自己:)

Answer 3

你的輸出越來越陌生號碼，因爲您的代碼不完全填充陣列（它打印出那些已經對這些存儲位置的內容）。

，不會產生代碼（你幾乎沒有）：

• 你應該通過整個數組的大小（0〜20）的迭代循環for（他們三個），請記住，在這些你試圖檢查值的循環，所以你需要經歷所有的值。
• 根據您的計數器（first,second），而不是基於i，分配給您的最終陣列。再次，i只是用來遍歷數組。這會導致您的陣列在這裏出現漏洞。當您輸入if報表並且僅在其各自的職位（i）中時，您只將值分配給final。
• 您的if對於數字大於零的語句不正確，它會檢查是否等於。
• 初始化first和second 0，而不是1

應該這樣做。作爲一個方面說明，你並不需要兩個單獨的計數器，first和second。你可以只使用一個，在你的第一個循環中增加它，然後在第二個循環中繼續增加它，等等。