Parencodings
Description
Let S = s1 s2...s2n be a well-formed string of parentheses. S can be encoded in two different ways:
q By an integer sequence P = p1 p2...pn where pi is the number of left parentheses before the ith right parenthesis in S (P-sequence). q By an integer sequence W = w1 w2...wn where for each right parenthesis, say a in S, we associate an integer which is the number of right parentheses counting from the matched left parenthesis of a up to a. (W-sequence). Following is an example of the above encodings: S (((()()()))) P-sequence 4 5 6666 W-sequence 1 1 1456 Write a program to convert P-sequence of a well-formed string to the W-sequence of the same string. Input
The first line of the input contains a single integer t (1 <= t <= 10), the number of test cases, followed by the input data for each test case. The first line of each test case is an integer n (1 <= n <= 20), and the second line is the P-sequence of a well-formed string. It contains n positive integers, separated with blanks, representing the P-sequence.
Output
The output file consists of exactly t lines corresponding to test cases. For each test case, the output line should contain n integers describing the W-sequence of the string corresponding to its given P-sequence.
Sample Input 2 6 4 5 6 6 6 6 9 4 6 6 6 6 8 9 9 9 Sample Output 1 1 1 4 5 6 1 1 2 4 5 1 1 3 9 Source |
提示
题意:
有一个括号序列它有两种表示方式:P-sequence,W-sequence。
P-sequence:序列是以从左到右,右括号的左边左括号的个数。
W-sequence:序列是以从左到右,右括号与之相匹配的左括号之间右括号个数(包括自身)。
思路:
模拟,将P-sequence序列转化为S序列(它原本的形式),再将S序列转化为W-sequence序列。
示例程序
Source Code
Problem: 1068 Code Length: 1118B
Memory: 392K Time: 0MS
Language: GCC Result: Accepted
#include <stdio.h>
int main()
{
int t,i,n,x,i1,top,k,i2;
char ch[300];
scanf("%d",&t);
for(i=1;t>=i;i++)
{
scanf("%d",&n);
top=0;
k=0;
for(i1=1;n>=i1;i1++)
{
scanf("%d",&x);
for(i2=x-k;i2>=1;i2--)
{
ch[top]='(';
top++;
}
k=x; //记录上一个左括号的个数
ch[top]=')';
top++;
}
x=0;
for(i1=0;top>i1;i1++)
{
k=0;
if(ch[i1]==')')
{
for(i2=i1;i2>=0&&ch[i2]!='(';i2--)
{
if(ch[i2]!='0')
{
k++;
}
}
if(i2>=0)
{
ch[i2]='0'; //匹配完成以后就不要了
}
if(x==0)
{
printf("%d",k);
x=1;
}
else
{
printf(" %d",k);
}
}
}
printf("\n");
}
return 0;
}