HDU 1082 Matrix Chain Multiplication by kuangbin

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1082

writed by kuangbin

题目大意:

大意就是给你n个矩阵,再给你一个矩阵链,先判断矩阵链是否合法,再计算这个矩阵链要做多少次乘法。

代码:

#include<stdio.h>
#include<string.h>
int a[26][2];
int zhan[1000][2];
int top;
int sum;
char str[1000];
int jin(int x)
{
zhan[top][0]=a[x][0];
zhan[top][1]=a[x][1];
top++;
return 0;
}
int chu()
{
if(zhan[top-2][1]!=zhan[top-1][0])return 1;
sum+=zhan[top-1][0]*zhan[top-1][1]*zhan[top-2][0];
zhan[top-2][1]=zhan[top-1][1];
top--;
return 0;
}
int main()
{
//freopen("test.in","r",stdin);
// freopen("test.out","w",stdout);
int n,i,j,x,y;
char ch;
scanf("%d",&n);

for(i=0;i<n;i++)
{
getchar();
scanf("%c %d %d",&ch,&x,&y);
// printf("%c %d %d\n",ch,x,y);
a[ch-'A'][0]=x;
a[ch-'A'][1]=y;
}
while(scanf("%s",&str)!=EOF)
{
top=sum=0;
int len=strlen(str);
if(len==1)
{
printf("0\n");
continue;
}
int flag=0;
for(i=0;i<len&&!flag;i++)
{
if(str[i]=='(')continue;
if(str[i]==')')flag=chu();
else jin(str[i]-'A');
if(flag) break;
}
if(flag) printf("error\n");
else printf("%d\n",sum);
}
return 0;
}
原文地址:https://www.cnblogs.com/kuangbin/p/2262172.html