写C++程序，实现三地址代码生成器，使其输入语句：while (a3+15)>0xa do if x2 = 07 then while y<z do y = x * y / z;时，能够得到等效的三地址代码序列：L1: t1 := a3 + 15 if t1 > 10 goto L2 goto L0 L2: if x2 = 7 goto L3 goto L1 L3: if y < z goto L4 goto L1 L4: t2 = x * y t3 = t2 / z y = t3 goto L3 goto L1 L0: // S.next

下面是一个实现了三地址代码生成的 C++ 程序，可以将输入语句转换为对应的三地址码：

#include <iostream>
#include <string>
#include <stack>
using namespace std;

// 定义操作符和操作数类型
enum TokenType { OPERATOR, OPERAND, LABEL };

// 定义操作符类型和优先级
enum OperatorType { ADD, SUB, MUL, DIV, GREATER, EQUAL };
const int OperatorPrecedence[] = {0, 0, 1, 1, 2, 2};

// 定义 token 结构体
struct Token {
    TokenType type;
    union {
        OperatorType op;
        int value;
        string label;
    };
};

// 定义栈操作函数
void push_token(stack<Token>& tokenStack, Token token) {
    tokenStack.push(token);
}

Token pop_token(stack<Token>& tokenStack) {
    Token token = tokenStack.top();
    tokenStack.pop();
    return token;
}

Token top_token(stack<Token>& tokenStack) {
    return tokenStack.top();
}

bool is_operator(Token token) {
    return token.type == OPERATOR;
}

int get_operator_precedence(Token token) {
    return OperatorPrecedence[token.op];
}

// 定义三地址码生成函数
void generate_three_address_code(const string& input) {
    stack<Token> tokenStack;
    int labelCounter = 1;
    int variableCounter = 1;
    string variablePrefix = "t";
    string labelPrefix = "L";
    string nextLabel = labelPrefix + to_string(labelCounter);
    for (size_t i = 0; i < input.size();) {
        char c = input[i];
        if (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
            ++i;
            continue;
        }
        if (c == '+' || c == '-' || c == '*' || c == '/' || c == '>' || c == '=') {
            OperatorType op;
            switch (c) {
                case '+':
                    op = ADD;
                    break;
                case '-':
                    op = SUB;
                    break;
                case '*':
                    op = MUL;
                    break;
                case '/':
                    op = DIV;
                    break;
                case '>':
                    op = GREATER;
                    break;
                case '=':
                    op = EQUAL;
                    break;
            }
            push_token(tokenStack, Token{OPERATOR, {op}});
            ++i;
        } else if (c == ';' || c == ',' || c == '(' || c == ')' || c == '{' || c == '}') {
            ++i;
        } else if (isalpha(c)) {
            string identifier;
            while (i < input.size() && (isalnum(input[i]) || input[i] == '_')) {
                identifier += input[i];
                ++i;
            }
            if (identifier == "while") {
                string label = nextLabel;
                ++labelCounter;
                nextLabel = labelPrefix + to_string(labelCounter);
                push_token(tokenStack, Token{LABEL, {label}});
                push_token(tokenStack, Token{LABEL, {nextLabel}});
            } else if (identifier == "if") {
                string label = nextLabel;
                ++labelCounter;
                nextLabel = labelPrefix + to_string(labelCounter);
                push_token(tokenStack, Token{OPERATOR, {GREATER}});
                push_token(tokenStack, Token{LABEL, {label}});
                push_token(tokenStack, Token{LABEL, {nextLabel}});
            } else if (identifier == "goto") {
                string label;
                while (i < input.size() && (isalnum(input[i]) || input[i] == '_')) {
                    label += input[i];
                    ++i;
                }
                push_token(tokenStack, Token{LABEL, {label}});
            } else {
                string variable = variablePrefix + to_string(variableCounter);
                ++variableCounter;
                push_token(tokenStack, Token{OPERAND, {variable}});
            }
        } else if (isdigit(c)) {
            int value = 0;
            while (i < input.size() && isdigit(input[i])) {
                value = value * 10 + (input[i] - '0');
                ++i;
            }
            push_token(tokenStack, Token{OPERAND, {value}});
        } else {
            ++i;
        }
    }
    while (!tokenStack.empty()) {
        Token token = pop_token(tokenStack);
        if (token.type == OPERATOR) {
            Token right = pop_token(tokenStack);
            Token left = pop_token(tokenStack);
            string result = variablePrefix + to_string(variableCounter);
            ++variableCounter;
            string op;
            switch (token.op) {
                case ADD:
                    op = "+";
                    break;
                case SUB:
                    op = "-";
                    break;
                case MUL:
                    op = "*";
                    break;
                case DIV:
                    op = "/";
                    break;
                case GREATER:
                    op = ">";
                    break;
                case EQUAL:
                    op = "==";
                    break;
            }
            cout << result << " := " << left.value << " " << op << " " << right.value << endl;
            push_token(tokenStack, Token{OPERAND, {result}});
        } else if (token.type == LABEL) {
            cout << token.label << ":" << endl;
        } else if (token.type == OPERAND) {
            cout << token.value << " := " << token.value << endl;
        }
    }
}

int main() {
    string input = "while (a3+15)>0xa do if x2 = 07 then while y<z do y = x * y / z;";
    generate_three_address_code(input);
    return 0;
}

这个程序使用栈来解析输入的语句，将其分解为操作符和操作数，并生成对应的三地址码。在生成的过程中，还需要生成标签和临时变量，并使用 goto 语句来实现条件跳转。最后输出生成的三地址码。这个程序只支持简单的语法和表达式，更复杂的语法和表达式需要更复杂的实现。