Create 1003_caesar_199.cpp

From https://vijos.org/p/1003/solution

VIJOS/1003_caesar_199.cpp

@@ -0,0 +1,131 @@
+#include<iostream>
+#include<cstdio>
+#include<string>
+#include<sstream>
+using namespace std;
+const char* alph = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+long long a;
+long long stand[15];
+
+long long jia(stringstream&);
+long long cheng(stringstream&);
+
+long long pow (long long a, long long b) {
+    long long ans = 1;
+    for (int i = 0; i < b; i++) ans *= a;
+    return ans;
+}
+
+bool check () {
+    string line; getline(cin, line);
+    for (a = 0; a < 10; a++) {
+        stringstream ss(line);
+        if (jia(ss) != stand[a]) return false;
+    }
+    return true;
+}
+
+int main ()
+{
+    int n;
+    string line; 
+    getline(cin, line);
+    for (a = 0; a < 10; a++) {
+        stringstream ss(line);
+        stand[a] = jia(ss);
+    }
+    cin >> n;
+    getchar();
+    for(int i = 0; i < n; i++) 
+        if (check()) cout << alph[i];
+    return 0;
+}
+
+long long pan(stringstream& ss) {
+    long long num = 0;
+    char c = 0;
+    ss >> c;
+    if (c == 'a') return (long long)a;
+    else {
+        ss.putback(c);
+        ss >> num;
+        return num;
+    }
+}
+
+long long getnum(stringstream& ss) {
+    long long b = 0;
+    char c = 0;
+    b = pan(ss);
+    ss >> c;
+    while (c == '^') {
+        long long d;
+        d = pan(ss);
+        b = pow(b, d);
+        c = 0;
+        ss >> c;
+    }
+    ss.putback(c);
+    return b;
+}
+
+long long cheng (stringstream& ss) {
+    char c = 0;
+    long long ans = 0;
+    long long num = 0;
+    ss >> c;
+    if (c == '(') ans = jia(ss);
+    else {
+        ss.putback(c);
+        ans = getnum(ss);
+    } 
+    while (ss >> c) {
+        switch (c) {
+            case ' ' :
+                continue;
+            case '*' :
+                ss >> c;
+                if (c == '(') num = jia(ss);
+                else {
+                    ss.putback(c);
+                    num = getnum(ss);
+                }
+                ans *= num;
+                break;
+            default : 
+                ss.putback(c); 
+                return ans;
+        }
+    }
+    return ans;
+}
+
+long long jia (stringstream& ss) {
+    char c = 0;
+    long long ans = 0;
+    ans = cheng(ss);
+    while (ss >> c) {
+        switch (c) {
+            case ' ' :
+                continue;
+            case '+' : 
+                ans += cheng(ss);
+                break; 
+            case '-' :
+                ans -= cheng(ss);
+                break; 
+            case ')' :
+                ss >> c;
+                while (c == '^') {
+                    long long b;
+                    b = pan(ss);
+                    ans = pow(ans, b);
+                    c = 0;
+                    ss >> c;
+                }
+                ss.putback(c);
+                return ans;
+        }     
+    }
+    return ans; 
+}