栈的应用 逆波兰式
#define _CRT_SECURE_NO_WARNINGS 1 #pragma once #include#include #include using namespace std; enum Type { OP_NUM, OP_SYMBOL, }; enum SYMBOL { ADD, SUB, MUL, DIV, }; struct Cell { Type _type; int _value; }; #include int CountRNP(Cell a[], size_t size) { assert(a); stack s; for (size_t i = 0; i < size; ++i) { if (a[i]._type == OP_NUM) { s.push(a[i]._value); } else { int right = s.top(); s.pop(); int left = s.top(); s.pop(); switch (a[i]._value) { case ADD: s.push(left + right); break; case SUB: s.push(left - right); break; case MUL: s.push(left*right); break; case DIV: s.push(left / right); break; } } } return s.top(); } void TestRNP() { //vector Cell a[] = { { OP_NUM, 12 }, { OP_NUM, 3 }, { OP_NUM, 4 }, { OP_SYMBOL, ADD }, { OP_SYMBOL, MUL }, { OP_NUM, 6 }, { OP_SYMBOL, SUB }, { OP_NUM, 8 }, { OP_NUM, 2 }, { OP_SYMBOL, DIV }, { OP_SYMBOL, ADD }, }; cout << "运算结果:" << CountRNP(a, sizeof(a) / sizeof(Cell)) << endl; } int main() { TestRNP(); getchar(); return 0; } |
本文标题:栈的应用 逆波兰式
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