delete pics to save space

2.442.cpp

@@ -0,0 +1,89 @@
+#include<cstdio>
+#include<stack>
+#include<iostream>
+#include<string>
+using namespace std;
+struct Matrix
+{
+	int a,b;
+	Matrix(int _a=0,int _b=0)
+	{
+		a=_a;
+		b=_b;
+	}
+};
+Matrix m[26];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	int n;
+	cin>>n;
+	for(int i=0;i<n;i++)
+	{
+		string name;
+		cin>>name;
+		int k=name[0]-'A';
+		cin>>m[k].a>>m[k].b;
+	}
+	string expr;
+	while(cin>>expr)
+	{
+		int len=expr.size();
+		bool error=0;
+		int ans=0;
+		stack<Matrix> s;
+		for(int i=0;i<len;i++)
+		{
+			if(isalpha(expr[i])) s.push(m[expr[i]-'A']);
+			else if(expr[i]==')')
+			{
+				Matrix m2=s.top();s.pop();
+				Matrix m1=s.top();s.pop();
+				if(m1.b!=m2.a){error=1;break;}
+				ans+=m1.a*m1.b*m2.b;
+				s.push(Matrix(m1.a,m2.b));
+			}
+		}
+		if(error) printf("error\n");
+		else printf("%d\n",ans);
+	}
+	return 0;
+}
+/*
+Sample Input
+9
+A 50 10
+B 10 20
+C 20 5
+D 30 35
+E 35 15
+F 15 5
+G 5 10
+H 10 20
+I 20 25
+A
+B
+C
+(AA)
+(AB)
+(AC)
+(A(BC))
+((AB)C)
+(((((DE)F)G)H)I)
+(D(E(F(G(HI)))))
+((D(EF))((GH)I))
+Sample Output
+0
+0
+0
+error
+10000
+error
+3500
+15000
+40500
+47500
+15125
+*/