64 lines
1.9 KiB
C++
64 lines
1.9 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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stack<int> n;
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int s, x, y;
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/**
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测试用例 ：
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3.5.2.-*7.+@ 3*(5–2)+7 16
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3.5.2.-*#:7 2 3#.+@ 3*(5–2)+(7+2)*(2+3) 54
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*/
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//快读
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inline int read() {
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int s = 0, w = 1;
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char ch = getchar();
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while (ch < '0' || ch > '9') if (ch == '-') w = -1, ch = getchar();
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while (ch >= '0' && ch <= '9') s = s * 10 + ch - '0', ch = getchar();
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return s * w;
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}
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int main() {
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char ch;
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do { //(1)上来就读入，读完了再看是不是结束符，就是干了再说~
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ch = getchar(); //(2)读入字符的办法
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//对增加的条件进行判断
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if (ch == '#') {
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//读入一个:
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char x = getchar();//放弃掉
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int a = read();
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int b = read();
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int c = read();
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n.push((a + b) * (b + c));
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//read会吃掉最后的#结束符
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x = getchar(); //再吃一个.
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//cout<<endl;
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} else if (ch >= '0' && ch <= '9') s = s * 10 + ch - '0'; //(3)按字符读入转为数字的办法
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else if (ch == '.') //表示数字结束
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n.push(s), s = 0; //入栈，重新计数
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else if (ch != '@') { //操作符
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x = n.top();
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n.pop();
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y = n.top();
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n.pop();
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switch (ch) {
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case '+':
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n.push(y + x);
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break;
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case '-':
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n.push(y - x); //注意顺序
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break;
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case '*':
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n.push(y * x);
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break;
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case '/':
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n.push(y / x); //注意顺序
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break;
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}
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}
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} while (ch != '@');
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printf("%d\n", n.top());
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return 0;
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} |