我有一个处理在C中创建程序的任务，其中用户必须插入3个整数并根据输入，它为用户提供一个三角形类型（只有它有效）才能用这些值创建。
代码本身有效，我已经设法插入一些循环来测试条件并使其更加健壮。
但是，我想为用户提供再次尝试不同结果的选项，或者只是关闭程序。我有一种感觉，我必须添加另一个while循环但是我不确定在哪里以及如何使程序以这种方式工作。
理想情况下，循环将替换结尾处的输出，或者在用户根据输入获得无效三角形的情况下。当这些情况发生时，我希望它能让用户选择重试或退出程序
请参阅我的代码：
#include <stdio.h>
int main()
{
/*** Declaring triangle variable sides ****/
float sideA;
float sideB;
float sideC;
char ch;
printf("Lets explore triangles! Please insert a value for side 'A' of your triangle:");
while(scanf("%f", &sideA) != 1)
{
printf("You inserted an incorrect value. Please insert a number for side 'A' of your triangle:");
while ( (ch=getchar()) != '\n' );
}
printf(" Now insert a value for side 'B' of your triangle:");
while(scanf("%f", &sideB) != 1 )
{
printf("You inserted an incorrect value. Please insert a number for side 'B' of your triangle:");
while ( (ch=getchar()) != '\n' );
}
printf(" And finally, insert a value for side 'C' of your triangle:");
while(scanf("%f", &sideC) != 1 )
{
printf("You inserted an incorrect value. Please insert a number for side 'C' of your triangle:");
while ( (ch=getchar()) != '\n' );
}
/*** List of conditions based on user input to identify if the triangle is valid and if so, what type of triangle they get***/
if(sideA <=0 || sideB<=0 || sideC <=0)
{
printf("YOUR TRIANGLE IS 'INVALID'.\n\n");
printf("REASON: You cannot have a triangle with any side having a value of 0.\n");
printf("Please exit the program and restart it to try again.\n");
}
else
if( (sideA+sideB<sideC) || (sideB+sideC<sideA) || (sideC+sideA<sideB) )
{
printf("YOUR TRIANGLE IS 'INVALID'.\n\n");
printf("REASON: The sum of every pair of sides must be greater than the third side of a triangle.!\n");
printf("Please exit the program and restart it to try again.\n");
}
else
if( (sideA==sideC && sideB==sideC) || (sideB==sideA && sideC==sideA) || (sideC==sideB && sideA==sideB) ) /*** Code to determine EQUILATERAL TRIANGLE***/
{
printf("YOUR TRIANGLE IS 'VALID'.\n");
printf(" Your input creates a valid EQUILATERAL triangle.\n");
}
else
if( (sideA == sideB ) || (sideB == sideC ) || (sideC == sideA ) )/*** Code to determine ISOSCELES TRIANGLE***/
{
printf("YOUR TRIANGLE IS 'VALID'.\n");
printf("Your input creates a valid ISOSCELES triangle.\n");
}
else
if( (sideA!= sideB) && (sideB != sideC) )/*** Code to determine SCALENE triangle ***/
{
printf("YOUR TRIANGLE IS 'VALID'.\n");
printf("Your input creates a valid SCALENE triangle.\n");
}
else
{
printf("You have inserted invalid range of values, as a result your triangle is invalid.\n");
printf("Please exit the program and restart it to try again.\n");
printf("Goodbye.\n");
}
return(0);
}
答案 0 :(得分：2)
使用do while循环可以轻松实现。
尝试此算法
char a;
do
{
/* Your code */
printf(" Do you want to do more ( Y/N ) " );
scanf( " %c",a );
} while( a == 'Y' || a == 'y' );
现在，这是代码中实现的代码
#include <string.h>
#include <stdio.h>
int main()
{
/*** Declaring triangle variable sides ****/
float sideA;
float sideB;
float sideC;
char a;
do
{
printf("Lets explore triangles! Please insert a value for side 'A' of your triangle:");
while(scanf("%f", &sideA) != 1)
{
printf("You inserted an incorrect value. Please insert a number for side 'A' of your triangle:");
while ( (getchar()) != '\n' );
}
printf(" Now insert a value for side 'B' of your triangle:");
while(scanf("%f", &sideB) != 1 )
{
printf("You inserted an incorrect value. Please insert a number for side 'B' of your triangle:");
while ( (getchar()) != '\n' );
}
printf(" And finally, insert a value for side 'C' of your triangle:");
while(scanf("%f", &sideC) != 1 )
{
printf("You inserted an incorrect value. Please insert a number for side 'C' of your triangle:");
while ( (getchar()) != '\n' );
}
/*** List of conditions based on user input to identify if the triangle is valid and if so, what type of triangle they get***/
if(sideA <=0 || sideB<=0 || sideC <=0)
{
printf("YOUR TRIANGLE IS 'INVALID'.\n\n");
printf("REASON: You cannot have a triangle with any side having a value of 0.\n");
}
else if( (sideA+sideB<sideC) || (sideB+sideC<sideA) || (sideC+sideA<sideB) )
{
printf("YOUR TRIANGLE IS 'INVALID'.\n\n");
printf("REASON: The sum of every pair of sides must be greater than the third side of a triangle.!\n");
}
else if( (sideA==sideC && sideB==sideC) || (sideB==sideA && sideC==sideA) || (sideC==sideB && sideA==sideB) ) /*** Code to determine EQUILATERAL TRIANGLE***/
{
printf("YOUR TRIANGLE IS 'VALID'.\n");
printf(" Your input creates a valid EQUILATERAL triangle.\n");
}
else if( (sideA == sideB ) || (sideB == sideC ) || (sideC == sideA ) )/*** Code to determine ISOSCELES TRIANGLE***/
{
printf("YOUR TRIANGLE IS 'VALID'.\n");
printf("Your input creates a valid ISOSCELES triangle.\n");
}
else if( (sideA!= sideB) && (sideB != sideC) )/*** Code to determine SCALENE triangle ***/
{
printf("YOUR TRIANGLE IS 'VALID'.\n");
printf("Your input creates a valid SCALENE triangle.\n");
}
else
{
printf("You have inserted invalid range of values, as a result your triangle is invalid.\n");
}
printf("Do you want to try again ( Y/N )");
scanf(" %c",&a);
}while( a=='Y' || a=='y' );
return(0);
}
答案 1 :(得分：0)
将main()内的所有代码放在一个单独的函数中，例如HandleOneTriangle()
然后在main中你把这个循环（伪代码）：
main()
{
while(true)
{
HandleOneTriangle();
boll answer = AskUserIfHeWantsOneMore();
if(!answer) break;
}
SayGoodbye();
}