C程序計算有多少合格或不合格的等級和退出時負數輸入

Question

我是一個新手，C語言程序設計和我們仍然在循環開始。對於今天我們的工作，我們任務是創建一個計算有多少合格或不合格的等級也有，但是當一個負數輸入迴路斷開一個做，而計劃。另外，跳過100以上的數字。這是我的計劃：

#include<stdio.h> 
#include<conio.h> 

int main() 
{ 
int grade, pass, fail; 

pass = 0; 
fail = 0; 

do { 
    printf("Enter grade:\n"); 
    scanf("%d", &grade); 
    printf("Enter -1 to end loop"); 
} 

while(grade == -1){ 
    if(grade < 100){ 
     if(grade >= 50){ 
     pass = pass + 1; 
     } 
     else if { 
     fail = fail + 1; 
     } 
    } 
    break; 
} 
printf("Pass: %d", pass); 
printf("Fail: %d", fail); 

getch(); 
return 0; 
} 

有人能告訴我如何改善或者我哪裏錯了？

Answer 1

您需要放置在do和while之間循環的所有代碼。

do { 
    printf("Enter -1 to end loop"); 
    printf("Enter grade:\n"); 
    scanf("%d", &grade);   

    if(grade <= 100 && grade >= 0) { 
      if(grade >= 50){ 
       pass = pass + 1; 
      } 
      else { 
       fail = fail + 1; 
      } 
    } 

} while(grade >= 0); 

一個do-while循環的一般結構爲：

do { 
    // all of the code in the loop goes here 

} while (condition); 
// <-- everything from here onwards is outside the loop 

Answer 2

do { 
    // stuff 
} 
while { 
    // more stuff 
} 

是混合2個概念放在一起：在while loop和do while loop - 我想通過重構那塊開始。

Answer 3

有關問題的邏輯是：

1. 保持運行時輸入不是-1。如果輸入爲-1，則打破/退出執行並顯示輸出。
   1. 輸入級。
   2. 如果等級爲小於或等於100，或者大於或等於0執行合格/不合格檢查：
      1. 如果等級是大於或等於50，則該人已經過去了。增加通過次數。
      2. 如果等級低於50，那個人已經失敗。增加失敗的考試數量。

jh314's layout logic是正確的，但不能解決執行邏輯：

int grade, pass, fail; 

    pass = 0; 
    fail = 0; 

    do { 
    printf("Enter -1 to end loop"); 
    printf("Enter grade:\n"); 
    scanf("%d", &grade); 

    //you want grades that are both less than or equal to 100 
    //and greater than or equal to 0 
    if(grade <= 100 && grade >= 0){ 
      if(grade >= 50){ 
       pass = pass + 1; 
      } 
      //if the grades are less than 50, that person has failed. 
      else { 
       fail = fail + 1; 
      } 
    } 

    } while(grade != -1); 

    printf("Pass: %d", pass); 
    printf("Fail: %d", fail); 

Answer 4

#include <stdio.h> 
#include <conio.h> 

int main() 
{ 
    int grade, pass, fail; 

    pass = 0; 
    fail = 0; 

    do { 
     printf("\nEnter grade:\n"); 
     scanf("%d", &grade); 
     printf("Enter -1 to end loop"); 

     if (grade < 100 && grade >= 50) 
      pass = pass + 1; 
     else 
      fail = fail + 1; 
     printf("\nPass: %d", pass); 
     printf("\nFail: %d", fail); 
    } 
    while (grade >= 0); 

    getch(); 
}