37 lines
945 B
C++
37 lines
945 B
C++
#include <bits/stdc++.h>
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using namespace std;
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// 判断字符是否是操作符
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bool isOp(string c) {
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return c == "+" || c == "-" || c == "*" || c == "/";
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}
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string prefixToPostfix(string s) {
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stack<string> stk;
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for (int i = s.size() - 1; i >= 0; i--) {
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string c = string(1, s[i]);
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if (isOp(c)) { // 操作符
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string a = stk.top();
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stk.pop();
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string b = stk.top();
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stk.pop();
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stk.push(a + b + c);
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} else
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stk.push(c); // 字母a~z
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}
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return stk.top();
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}
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int main() {
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// * + 12 23 * 3 + 45 6
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string prefix = "*+ab*c+de";
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string postfix = prefixToPostfix(prefix);
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cout << "前缀表达式: " << prefix << endl;
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cout << "后缀表达式: " << postfix << endl;
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return 0;
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}
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/*
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Prefix Expression: *+ab*c+de
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Postfix Expression: ab+cde+**
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Infix Expression: ((a+b)*(c*(d+e)))
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*/ |