'commit'

TangDou/CSP-J/J2-2022/expr_4_QiuZhi_LuoJi_JianHuaVersion.cpp

@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+/*
+0&(1|0)|(1|1|1&0)
+答案：1
+
+(0|1&0|1|1|(1|1))&(0&1&(1|0)|0|1|0)&0
+答案：0
+*/
+unordered_map<char, int> h{{'|', 1}, {'&', 2}};
+stack<int> num;
+stack<char> op;
+
+void eval() {
+    int a = num.top();
+    num.pop();
+
+    int b = num.top();
+    num.pop();
+
+    char p = op.top();
+    op.pop();
+
+    int r;
+    if (p == '|')
+        r = b | a;
+    else if (p == '&')
+        r = b & a;
+    num.push(r);
+}
+
+int main() {
+    string s;
+    cin >> s;
+    for (int i = 0; i < s.size(); i++) {
+        if (isdigit(s[i]))
+            num.push(s[i] - '0');
+        else if (s[i] == '(')
+            op.push(s[i]);
+        else if (s[i] == ')') {
+            while (op.top() != '(') eval();
+            op.pop();
+        } else {
+            while (op.size() && h[op.top()] >= h[s[i]]) eval();
+            op.push(s[i]);
+        }
+    }
+    while (op.size()) eval();
+
+    printf("%d\n", num.top());
+    return 0;
+}