📄 pro.txt
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//若B→αAβ (β≠>ε)，则把FIRST(β)-{ε}加入FOLLOW(A)中
if(IsTerminate(proNode[j].rightSym[k+1]))
//如果β为终结符，则将其直接加入FOLLOW(A)中
AddChar(unTInfo[i].follow,proNode[j].rightSym[k+1]);
else { //如果β为非终结符，则将FIRST(β)-{ε}加入FOLLOW(A)中
int rightSymLoc = GetUTLoaction(UnTerminate,proNode[j].rightSym[k+1]);
int len = strlen(unTInfo[rightSymLoc].first);
for(int l = 0 ; l < len ; l++) {
if(unTInfo[rightSymLoc].first[l] != '^')
AddChar(unTInfo[i].follow,unTInfo[rightSymLoc].first[l]);
}
}
}
}
}
}
}
}
void SetSelect(ProNode proNode[],UnTInfo unTInfo[]) {//设置Select集合
bool isNull,isVT;
for(int i = 0 ;i < proNum; i++) { //扫描每一个产生式，求出Select集合
if(IsTerminate(proNode[i].rightSym[0])) {
//如果产生式的右边第一字符为终结符，则将其加入select集
AddChar(select[i],proNode[i].rightSym[0]);
}
else if(proNode[i].rightSym[0] == '^')
//如果产生式的右边字符为ε,则应将左边字符的follow集加入select集
AddCharToChar(select[i],unTInfo[GetUTLoaction(UnTerminate,proNode[i].leftSym)].follow);
else {
isVT = false;
isNull = true;
for(int j = 0; j < proNode[i].length; j++) {
//产生式右边的第一个字符为非终结符，则逐个分析
if(!IsTerminate(proNode[i].rightSym[j])) {
//若α=X1X2 … Xnα′，其中Xi∈VN , 1≤i≤n；
//若ε∈FIRST(X1),则将FIRST(X2)中的一切非ε的终结符加进FIRST(α),
//FIRST(α)则应加入select集；以此类推
int rightSymLoc = GetUTLoaction(UnTerminate,proNode[i].rightSym[j]);
int firLen = strlen(unTInfo[rightSymLoc ].first);
for(int k = 0 ; k < firLen ; k++)
if(unTInfo[rightSymLoc ].first[k] != '^')
AddChar(select[i],unTInfo[rightSymLoc].first[k]);
if(!IsNull(proNode[i].rightSym[j])) {
//如果该非终结符不能推出空字符则应停止循环
isNull = false;
break;
}
}
else { //遇到了终结符号，此时也应终止循环
isVT = true;
break;
}
}
if(isVT&&isNull) //处理像E->ABaβ的产生式的情况
AddChar(select[i],proNode[i].rightSym[j]);
if(j == proNode[i].length) {
//若α=X1X2 … Xnα′，其中Xi∈VN , 1≤i≤n；
//若对于一切1≤i≤n,ε∈FIRST(Xi)，则将follow(α)加入select集合
int leftSymLoc = GetUTLoaction(UnTerminate,proNode[i].leftSym);
AddCharToChar(select[i],unTInfo[leftSymLoc].follow);
}
}
}
}
void SetSheet(ProNode proNode[],UnTInfo unTInfo[]) { //构造分析表
int selLen ;
int rowLoc,colLoc;
for(int i = 0; i < proNum ; i++) {
selLen = strlen(select[i]);
for(int j = 0 ; j < selLen ; j++) {
rowLoc = GetUTLoaction(UnTerminate,proNode[i].leftSym);
colLoc = GetTLocaction(Terminate,select[i][j]);
sheet[rowLoc][colLoc] = proNode[i];
}
}
}
void InputSym() { //输入字符串函数
InitQueue(Remain);
cout<<"请输入要分析的字符串(以'#'结束):"<<endl;
char tmpChar;
int i = 0 ;
cin>>tmpChar;
while(tmpChar != '#') {
EnQueue(Remain,tmpChar);
cin>>tmpChar;
}
EnQueue(Remain,tmpChar);
}
void Scan() { //分析扫描的主控程序
int i = 0 ;
int step = 1;
int rightLoc;
int leftLoc;
char a;
char x;
bool flag = true;
//SymStack[i] = '#';
//SymStack[++i] = UnTerminate[0]; //'#' 、开始符号入栈
//SqStack s;
SqStack SymStack; //符号栈
InitStack(SymStack);
cout<<"步骤"<<"\t"<<"符号栈"<<"\t\t"<<"读入符号"<<"\t"<<"剩余符号串"<<"\t"<<"使用产生式"<<endl;
cout<<step++<<"\t";
Push(SymStack,'#');
Push(SymStack,UnTerminate[0]); //'#' 、开始符号入栈
PrintSym(SymStack);
a = GetSym(Remain); //读入第一个符号
cout<<a<<"\t\t";
while(flag) {
PrintRemain(Remain);
x = Pop(SymStack); //从栈中弹出符号
leftLoc = GetUTLoaction(UnTerminate,x);
rightLoc = GetTLocaction(Terminate,a);
PrintSheet(leftLoc,rightLoc);
cout<<"\n";
if(IsTerminate(x)){
if(x == a) {
a = GetSym(Remain);
cout<<step++<<"\t";
PrintSym(SymStack);
cout<<a<<"\t\t";
}
else {
flag = false;
Error();
}
}
else if(x == '#') {
if(x == a) { //分析成功
Success();
flag = 0 ;
}
else {
flag = 0 ;
Error();
}
}
else if(sheet[GetUTLoaction(UnTerminate,x)][GetTLocaction(Terminate,a)].leftSym \
!= '\0' ) { // X ∈Vn查分析表
//Pop(SymStack);
leftLoc = GetUTLoaction(UnTerminate,x);
rightLoc = GetTLocaction(Terminate,a);
if(sheet[leftLoc][rightLoc].rightSym[0] != '^') {
//若X1X2…Xn != ε，则反顺序进栈
int rightLen = strlen(sheet[leftLoc][rightLoc].rightSym);
for(int i = rightLen - 1; i >=0 ; i--) {
Push(SymStack,sheet[leftLoc][rightLoc].rightSym[i]);
}
cout<<step++<<"\t";
PrintSym(SymStack);
cout<<a<<"\t\t";
}
else {
cout<<step++<<"\t";
PrintSym(SymStack);
cout<<a<<"\t\t";
}
}
else {
flag = 0;
Error();
}
}
}
char GetSym(LinkQueue &q) {
if(q.front == q.rear) return NULL;
QueuePtr p = (QueuePtr)malloc(sizeof(QNode));
p = q.front->next;
char tmp = p->data;
q.front->next = p->next;
if(q.rear == p) q.rear = q.front;
free(p);
return tmp;
}
void PrintSym(SqStack &s) { //显示符号栈 符号
char* i ;
for( i = s.base ; i < s.top;i++)
cout<<*i;
cout<<"\t\t";
}
void PrintRemain(LinkQueue &q) { //显示剩余符号串
QueuePtr d ;
char tmp;
if(q.front->next != NULL) {
d =q.front->next;
do {
tmp = d->data;
cout<<tmp;
d = d->next;
}while(tmp != '#');
cout<<"\t\t";
}
else return ;
}
void PrintSheet(int row,int col) { //显示所使用产生式
if(row != -1 && col != -1) {
cout<<sheet[row][col].leftSym<<sheet[row][col].midSym[0]<<sheet[row][col].midSym[1];
for(int j = 0; j < sheet[row][col].length;j++)
cout<<sheet[row][col].rightSym[j];
}
else
cout<<" ";
}
void Success() {//分析成功
cout<<"Successful!"<<endl;
}
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