Parencodings
Time Limit: 1000MS | Memory Limit: 10000K | |
Total Submissions: 19550 | Accepted: 11804 |
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:
Write a program to convert P-sequence of a well-formed string to the W-sequence of the same string.
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
题目分析:
poj的一道英文题目,读了好久啊还借助了别人的翻译指导。此题多组处理数据,每组输入n个数,每个a[i]代表当前对应的右括号前面共有多少个左括号。
比如:n=6, 4 5 6 6 6 6 。 对应第一个右括号前有4个左括号,第二个右括号前有5个左括号,不过千万不要落下第一个右括号啊,以此类推下去。。。。。。
现在要求输出另一个数组,数组元素为当前右括号包含的括号总数!
比如:(()())
第一个右括号只包含自己,故为 1;
第二个右括号也只包含自己, 故为 1;
第三个右括号包含前面两个括号,再加上自己,故为 3.
所以应输出:1 1 3 ;
算法思路:根据n个数的数组模拟出原来的括号字符串,而我用的整形数组代替的,就是用1代表'(',用2代表‘)’,然后对这个整形数组处理。
样例解析:
(((()()()))))
1 1 112 12 12 2 2 2 2
标记数组:0 0 000 00 00 0 0 0 0
第一次处理:0 0 011..............等
标记数组遇到"2"则变成“1”。此时找到2了,则往2的前面去找1,也就是所谓的左括号,然后将找到的左括号标记为1,接下来将
该输出的数存入输出数组,计算公式为:(i-j+1)/2; i为右括号的下标,j为找到的匹配的左括号的下标。
Accepted的代码如下:
#include <stdio.h> #include <string.h> int a[30]; int b[100], e; int c[100]; int d[100], dd; int main() { int t, n; int i, j, k; scanf("%d", &t) ; while(t--) { e = 0; scanf("%d", &n); scanf("%d", &a[0] ); for(j=0; j<a[0]; j++) { b[e++] = 1; } b[e++]=2; for(i=1; i<n; i++) { scanf("%d", &a[i] ); for(j=0; j<(a[i]-a[i-1]); j++) { b[e++] = 1; } b[e++] = 2; } memset(c,0, sizeof(c)); dd = 0; for(i=0; i<e; i++ ) { if( b[i]==2 && c[i]==0 ) { c[i]=1; for(j=i-1; j>=0; j--) { if( b[j]==1 && c[j]==0 ) { c[j]=1; d[dd++] = (i-j+1)/2 ; break; } } } } for(k=0; k<dd; k++) { printf("%d%c", d[k],k==dd-1?' ':' ' ); } } return 0; }