我已经遵循了书中的所有内容，但我的平均分数每次都不及格。我已经多次调试我的程序，但无济于事。
我的最小可执行代码：
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#define MAX_TESTS 5
#define MAXQUESTION 10000
bool myread(const char * format, void * address) {
char buffer[1024];
fgets(buffer, sizeof buffer, stdin);
return sscanf(buffer, format, address) == 1;
}
struct struc {
int a;
int b;
int c;
int add;
int grade;
};
int sj(int n) {
int t;
t = rand() % n;
return t;
}
void ctm_i(struct struc * t) {
{
t -> a = sj(101);
t -> c = sj(4);
if (t -> c == 1) {
t -> b = sj(101 - (t -> a));
t -> add = (t -> a) + (t -> b);
} else {
t -> b = sj((t -> a) + 1);
t -> add = (t -> a) - (t -> b);
}
t -> grade = 0;
}
}
void tcm_i(struct struc * t, int n) {
int ad;
printf(" ***********************************************************************"
"*********\n");
printf(" ......................................................................."
".........\n");
printf(" Question %d\n\n", n + 1);
printf(" You have 3 attempts for this question\n\n");
if (t -> c == 1)
printf(" %d+%d= ", t -> a, t -> b);
else
printf(" %d-%d= ", t -> a, t -> b);
myread(" %d", & ad);
if (ad == t -> add)
{
t -> grade = 10;
printf(" You earned 10 marks\n\n");
} else {
printf("\n Incorrect, you have 2 attempts remaining\n\n");
printf(" ");
myread(" %d", & ad);
if (ad == t -> add)
{
t -> grade = 7;
printf(" You earned 7 marks\n\n");
} else {
printf("\n Incorrect, you have 1 attempt remaining\n\n");
printf(" ");
myread(" %d", & ad);
if (ad == t -> add)
{
t -> grade = 5;
printf(" You earned 5 marks\n\n");
} else {
t -> grade = 0;
printf("\n Failure, 0 mark\n\n");
printf("\n The correct answer is %d\n\n", t -> add);
}
}
}
printf(" ......................................................................."
".........\n");
printf(" ***********************************************************************"
"*********\n");
}
void quiz(char name[]) {
int rounds = 0;
int highest = 0;
int lowest = INT_MAX;
float allScore = 0;
float avg = 0.0;
int i, j, g = 0;
struct struc test[MAX_TESTS];
srand((unsigned) time(NULL));
for (;;) {
rounds++;
for (i = 0; i < MAX_TESTS; i++) // generate all questions
{
ctm_i( & test[i]);
for (j = 0; j < i; j++)
if (test[i].a == test[j].a && test[i].b == test[j].b && test[i].c == test[j].c)
//if question is already present
ctm_i( & test[i]); //then re-generate
}
printf("\n Are you ready? Press Enter key to continue. ");
myread("", NULL);
for (i = 1; i <= 5; i++) {
printf(" *******************************************************************"
"**"
"***********\n");
printf(" ..................................................................."
".."
"...........\n");
}
// Take quiz
for (i = 0; i < MAX_TESTS; i++)
tcm_i( & test[i], i);
printf(" End\n\n");
bool done = false;
bool unsure = true;
bool showS = true;
while (unsure) {
unsure = false;
puts("\n");
if (showS) {
puts(" Enter 'S' to show results");
}
puts(" Enter 'P' to play another round");
puts(" Enter 'R' to return to main menu");
char choice;
printf(" ");
myread(" %c", & choice);
printf("\n");
if (choice == 'r' || choice == 'R') {
done = true;
} else {
///////////////////////// Changes /////////////
g = 0;
// calculate total score for current round
for (i = 0; i < MAX_TESTS; i++) {
g += test[i].grade; //add score of each question
}
allScore += g; //add current round's score to total
avg = allScore / rounds; //average of all rounds
if (g > highest) {
highest = g;
}
if (g < lowest) {
lowest = g;
}
if (choice == 'S' || choice == 's') {
showS = false;
if (rounds == 1) {
printf(" Final score: %d/100\n", g); //display round score
printf(" ****** Player: %s ******\n", name);
} else {
printf(" Round %d score: %d/100\n", rounds, g); //display round score
printf(" Highest score: %d/100\n", highest);
printf(" Lowest score : %d/100\n", lowest);
printf(" Average score: %f/100\n", avg);
printf(" ****** Player: %s ******\n", name);
}
unsure = true;
} else if (choice == 'P' || choice == 'p') {
/// nothing to be done here
//we will display next test
} else {
puts(" Invalid input!");
unsure = true;
}
////////////////////////////////////
}
}
if (done)
break;
}
}
int main() {
char i1 = '1';
char name[25]; // ig;
printf("\n Welcome");
printf("\n");
while (i1 != 0) {
printf("\n");
//printf(" **********************Welcome %s! *********************\n", name);
printf(" ************************ Main Menu of Maths Quiz ***************************\n");
printf(" * 1.Enter Quiz *\n");
printf(" * 2.Quit *\n");
printf(" ****************************************************************************\n");
printf(" Please choose one from 1-2:\n");
printf(" ");
myread(" %c", & i1);
switch (i1) {
case '1':
printf("\n Enter Quiz:\n");
quiz(name); // calling quiz function defined in file "maincode.c"
break;
case '2':
printf(" Quit.\n\n");
}
}
return 0;
}
希望满足 MRE 的定义。 所以我剪掉了一些夸张的台词，我认为剩下的才是重要的。
答案 0 :(得分：0)
问题出在您的函数 quiz 中，尤其是在 while (unsure) 循环中。在此循环中，您将最新分数添加到运行总分中：
allScore += g; //add current round's score to total
这应该在每轮比赛中发生一次。但是如果用户输入“S”或无效的东西，你的程序就会设置
unsure = true;
这意味着循环将在下一轮开始之前再次运行。然后将最近的分数第二次添加到总计中。
最合乎逻辑的解决方案是将所有总计、最大值、最小值、平均值的计算移出 while 循环。循环有不同的用途：它用于用户交互和报告，而不是用于处理结果。
答案 1 :(得分：0)
可能再次对同一轮进行多次平均计算。保持flag来跟踪分数的统计，所以我们不会重复多次，直到游戏不再进行。
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#define MAX_TESTS 5
#define MAXQUESTION 10000
bool myread(const char * format, void * address) {
char buffer[1024];
fgets(buffer, sizeof buffer, stdin);
return sscanf(buffer, format, address) == 1;
}
struct struc {
int a;
int b;
int c;
int add;
int grade;
};
int sj(int n) {
int t;
t = rand() % n;
return t;
}
void ctm_i(struct struc * t) {
{
t -> a = sj(101);
t -> c = sj(4);
if (t -> c == 1) {
t -> b = sj(101 - (t -> a));
t -> add = (t -> a) + (t -> b);
} else {
t -> b = sj((t -> a) + 1);
t -> add = (t -> a) - (t -> b);
}
t -> grade = 0;
}
}
void tcm_i(struct struc * t, int n) {
int ad;
printf(" ***********************************************************************"
"*********\n");
printf(" ......................................................................."
".........\n");
printf(" Question %d\n\n", n + 1);
printf(" You have 3 attempts for this question\n\n");
if (t -> c == 1)
printf(" %d+%d= ", t -> a, t -> b);
else
printf(" %d-%d= ", t -> a, t -> b);
myread(" %d", & ad);
if (ad == t -> add)
{
t -> grade = 10;
printf(" You earned 10 marks\n\n");
} else {
printf("\n Incorrect, you have 2 attempts remaining\n\n");
printf(" ");
myread(" %d", & ad);
if (ad == t -> add)
{
t -> grade = 7;
printf(" You earned 7 marks\n\n");
} else {
printf("\n Incorrect, you have 1 attempt remaining\n\n");
printf(" ");
myread(" %d", & ad);
if (ad == t -> add)
{
t -> grade = 5;
printf(" You earned 5 marks\n\n");
} else {
t -> grade = 0;
printf("\n Failure, 0 mark\n\n");
printf("\n The correct answer is %d\n\n", t -> add);
}
}
}
printf(" ......................................................................."
".........\n");
printf(" ***********************************************************************"
"*********\n");
}
void quiz(char name[]) {
int rounds = 0;
int highest = 0;
int lowest = INT_MAX;
float allScore = 0;
float avg = 0.0;
int i, j, g = 0;
struct struc test[MAX_TESTS];
srand((unsigned) time(NULL));
for (;;) {
rounds++;
for (i = 0; i < MAX_TESTS; i++) // generate all questions
{
ctm_i( & test[i]);
for (j = 0; j < i; j++)
if (test[i].a == test[j].a && test[i].b == test[j].b && test[i].c == test[j].c)
//if question is already present
ctm_i( & test[i]); //then re-generate
}
printf("\n Are you ready? Press Enter key to continue. ");
myread("", NULL);
for (i = 1; i <= 5; i++) {
printf(" *******************************************************************"
"**"
"***********\n");
printf(" ..................................................................."
".."
"...........\n");
}
// Take quiz
for (i = 0; i < MAX_TESTS; i++)
tcm_i( & test[i], i);
printf(" End\n\n");
bool done = false;
bool unsure = true;
bool showS = true;
bool acct = false;
while (unsure) {
unsure = false;
puts("\n");
if (showS) {
puts(" Enter 'S' to show results");
}
puts(" Enter 'P' to play another round");
puts(" Enter 'R' to return to main menu");
char choice;
printf(" ");
myread(" %c", & choice);
printf("\n");
if (choice == 'r' || choice == 'R') {
done = true;
} else {
///////////////////////// Changes /////////////
if (false == acct) {
g = 0;
// calculate total score for current round
for (i = 0; i < MAX_TESTS; i++) {
g += test[i].grade; //add score of each question
}
allScore += g; //add current round's score to total
avg = allScore / rounds; //average of all rounds
if (g > highest) {
highest = g;
}
if (g < lowest) {
lowest = g;
}
acct = true;
}
if (showS &&(choice == 'S' || choice == 's')) {
showS = false;
if (rounds == 1) {
printf(" Final score: %d/100\n", g); //display round score
printf(" ****** Player: %s ******\n", name);
} else {
printf(" Round %d score: %d/100\n", rounds, g); //display round score
printf(" Highest score: %d/100\n", highest);
printf(" Lowest score : %d/100\n", lowest);
printf(" Average score: %f/100\n", avg);
printf(" ****** Player: %s ******\n", name);
}
unsure = true;
} else if (choice == 'P' || choice == 'p') {
/// nothing to be done here
//we will display next test
} else {
puts(" Invalid input!");
unsure = true;
}
////////////////////////////////////
}
}
if (done)
break;
}
}
int main() {
char i1 = '1';
char name[25]; // ig;
printf("\n Welcome");
printf("\n");
while (i1 != 0) {
printf("\n");
//printf(" **********************Welcome %s! *********************\n", name);
printf(" ************************ Main Menu of Maths Quiz ***************************\n");
printf(" * 1.Enter Quiz *\n");
printf(" * 2.Quit *\n");
printf(" ****************************************************************************\n");
printf(" Please choose one from 1-2:\n");
printf(" ");
myread(" %c", & i1);
switch (i1) {
case '1':
printf("\n Enter Quiz:\n");
quiz(name); // calling quiz function defined in file "maincode.c"
break;
case '2':
printf(" Quit.\n\n");
}
}
return 0;
}
输出：
Enter 'S' to show results
Enter 'P' to play another round
Enter 'R' to return to main menu
s
Round 2 score: 47/100
Highest score: 50/100
Lowest score : 47/100
Average score: 48.500000/100
****** Player: ******