int main() {
int yearsToLoop;
cin >> yearsToLoop;
annual_stats* ptr = new annual_stats [yearsToLoop];
for (int i = 0; i < yearsToLoop; i++)
{
int annualYear;
cin >> annualYear;
ptr[i].year = annualYear;
for (int j = 0; j < NO_TEAMS; j++)
{
string team_name;
getline(cin, team_name, '\t');
strcpy(ptr[i].teams[j].team_name, team_name.c_str());
int games;
cin >> games;
ptr[i].teams[j].games = games;
float pts_per_game;
cin >> pts_per_game;
ptr[i].teams[j].pts_per_game = pts_per_game;
int total_points;
cin >> total_points;
ptr[i].teams[j].total_points = total_points;
int scrimmage_plays;
cin >> scrimmage_plays;
ptr[i].teams[j].scrimmage_plays = scrimmage_plays;
float yds_per_game;
cin >> yds_per_game;
ptr[i].teams[j].yds_per_game = yds_per_game;
float yds_per_play;
cin >> yds_per_play;
ptr[i].teams[j].yds_per_play = yds_per_play;
float first_per_game;
cin >> first_per_game;
ptr[i].teams[j].first_per_game = first_per_game;
int third_md;
cin >> third_md;
ptr[i].teams[j].third_md = third_md;
int third_att;
cin >> third_att;
ptr[i].teams[j].third_att = third_att;
int third_pct;
cin >> third_pct;
ptr[i].teams[j].third_pct = third_pct;
int fourth_md;
cin >> fourth_md;
ptr[i].teams[j].fourth_md = fourth_md;
int fourth_att;
cin >> fourth_att;
ptr[i].teams[j].fourth_att = fourth_att;
int fourth_pct;
cin >> fourth_pct;
ptr[i].teams[j].fourth_pct = fourth_pct;
int penalties;
cin >> penalties;
ptr[i].teams[j].penalties = penalties;
int pen_yds;
cin >> pen_yds;
ptr[i].teams[j].pen_yds = pen_yds;
string top_per_game;
cin >> top_per_game;
strcpy(ptr[i].teams[j].top_per_game, top_per_game.c_str());
int fum;
cin >> fum;
ptr[i].teams[j].fum = fum;
int lost;
cin >> lost;
ptr[i].teams[j].lost = lost;
int to;
cin >> to;
ptr[i].teams[j].to = to;
}
}
int numberOfC;
cin >> numberOfC;
for (int i = 0; i < numberOfC; i++)
{
string command;
cin >> command;
if(command == "qsort") {
string command2;
cin >> command2;
int num = atoi(command2.c_str());
if (num >= 2010)
{
string year;
year = command2;
string field;
cin >> field;
string order;
cin >> order;
qSortYearFieldOrder(year, field, order, ptr, yearsToLoop);
}
}
所以就在这里（部分）主要我获得所有输入然后使用一些输入调用函数。我目前正在使用qSortYearFieldOrder（年，字段，顺序，ptr，yearsToLoop）出错。
void qSortYearFieldOrder(string year, string field, string order, annual_stats* ptr, int amountYears) {
int yearIndex = 0;
if (amountYears == 1) {
yearIndex == 0;
}
else {
if (year == "2010") {
yearIndex = 0;
}
else if (year == "2011") {
yearIndex = 1;
}
else if (year == "2012") {
yearIndex = 2;
}
else if (year == "2013") {
yearIndex = 3;
}
else if (year == "2014") {
yearIndex = 4;
}
else if (year == "2015") {
yearIndex = 5;
}
}
if (field == "team_name") {
if (order == "decr") {
cout << "\n\nDecreasing Order" << endl;
for (int i = 0; i < NO_TEAMS; i++) {
cout << ptr[yearIndex].teams[i].team_name;
}
}
else if (order == "incr") {
cout << "\n\nIncreasing Order" << endl;
for (int i = 0; i < NO_TEAMS; i++) {
cout << ptr[yearIndex].teams[NO_TEAMS - 1 - i].team_name;
}
}
}
else if (field == "games") {
if (order == "decr") {
quicksortGames(ptr, 0, NO_TEAMS - 1, yearIndex, order);
cout << "TEAM" << "\t\t" << "Number Of Games Decreasing";
for (int i = 0; i < NO_TEAMS; i++) {
cout << ptr[yearIndex].teams[i].team_name << " " << ptr[yearIndex].teams[NO_TEAMS - 1 - i].games;
}
}
else if (order == "incr") {
quicksortGames(ptr, 0, NO_TEAMS - 1, yearIndex, order);
cout << "TEAM" << "\t\t" << "Number Of Games Increasing";
for (int i = 0; i < NO_TEAMS; i++) {
cout << ptr[yearIndex].teams[NO_TEAMS - 1 - i].team_name << " " << ptr[yearIndex].teams[i].games;
}
}
}
然后在这个函数中，我根据它所在的字段以及递增/递减顺序对代码进行排序。
void quicksortGames(annual_stats* pointer, int firstIndex, int lastIndex, int yearIndex, string order)
{
//declaring index variables
int pivotIndex, temp, index1, index2;
if(firstIndex < lastIndex)
{
//assigning first element index as pivot element
pivotIndex = pointer[yearIndex].teams[firstIndex].games;
index1 = pointer[yearIndex].teams[firstIndex].games;
index2 = pointer[yearIndex].teams[lastIndex].games;
//Sorting in Ascending order with quick sort
while(index1 < index2)
{
while(pointer[yearIndex].teams[index1].games <= pointer[yearIndex].teams[pivotIndex].games && index1 < lastIndex)
{
index1++;
}
while(pointer[yearIndex].teams[index2].games <= pointer[yearIndex].teams[pivotIndex].games)
{
index2--;
}
if(index1<index2)
{
//Swapping opertation
temp = pointer[yearIndex].teams[index1].games;
pointer[yearIndex].teams[index1].games = pointer[yearIndex].teams[index2].games;
pointer[yearIndex].teams[index2].games = temp;
}
}
//At the end of first iteration, swap pivot element with index2 element
temp = pointer[yearIndex].teams[pivotIndex].games;
pointer[yearIndex].teams[pivotIndex].games = pointer[yearIndex].teams[index2].games;
pointer[yearIndex].teams[index2].games = temp;
//Recursive call for quick sort, with partiontioning
quicksortGames(pointer, firstIndex, index2-1, yearIndex, order);
quicksortGames(pointer, index2+1, lastIndex, yearIndex, order);
}
}
此功能用于快速排序游戏。我是单独制作的，因为快速排序是递归的，因此我无法在上一个函数内快速排序。我从这个网站得到了快速排序：http://www.cprogramto.com/c-program-quick-sort/。
所以基本上，我正在尝试获取所有输入，将它们放在按字段/顺序排序的函数中，然后专门调用字段的快速排序。
代码编译，但每当我尝试使用qsort 2015游戏decr等等的代码运行代码时，我正在收到分段错误11错误。当我省略qsort时，我的代码运行并适用于其他排序算法（这里没有显示），所以我确信错误是在快速排序。有人请帮我看看我的错误到底在哪里？
答案 0 :(得分：2)
考虑：
pivotIndex = pointer[yearIndex].teams[firstIndex].games;
index1 = pointer[yearIndex].teams[firstIndex].games;
index2 = pointer[yearIndex].teams[lastIndex].games;
...
while(pointer[yearIndex].teams[index1].games <= pointer[yearIndex].teams[pivotIndex].games && index1 < lastIndex)
您将数组索引（index1，index2）设置为游戏数。
不能保证小于团队数组中的元素数。
所以你结束了访问团队数组的界限== segfault。
更多信息：将您的代码与您获得算法的网站进行比较：
...
index2 = lastIndex;
//Sorting in Ascending order with quick sort
while(index1 < index2)
{
while(array[index1] <= array[pivotIndex] && index1 < lastIndex)
{
index1++;
....
索引是数组中的位置，其中array [index]是值。在您的情况下，您正在正确地在（内部）while循环中进行比较：
while(pointer[yearIndex].teams[index1].games <= pointer[yearIndex].teams[pivotIndex].games && index1 < lastIndex)
但您错误地设置了索引：
index1 = pointer[yearIndex].teams[firstIndex].games;
为了使其更具体，假设有10支球队，但第一支球队（0号队）打了1000场比赛。然后你的代码执行此操作：
index1 = pointer[yearIndex].teams[0].games; // index1=1000
while(pointer[yearIndex].teams[1000].games <=
pointer[yearIndex].teams[1000].games && 1000 < 9)
问题是如果团队只有10支队伍，那么团队[1000]是无效的，当你在C中访问这样的界限时，你会得到一个段错误（如果你很幸运）或腐败的记忆和/或安全漏洞（如果你不幸）。
此外，在评论中建议学习源调试器（GDB或其他 - 取决于您的平台）对学习C至关重要。