Parencodings
Time Limit: 1000MS Memory Limit: 10000K
Total Submissions: 17169 Accepted: 10296
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 9Source
Tehran 2001
題意:
對於給出的原括號串,存在兩種數字密碼串:
1.p序列:當出現匹配括號對時,從該括號對的右括號開始往左數,直到最前面的左括號數,就是pi的值。
2.w序列:當出現匹配括號對時,包含在該括號對中的所有右括號數(包括該括號對),就是wi的值。
題目的要求:對給出的p數字串,求出對應的s串。串長均<=20.
提示:在處理括號序列時可以使用一個小技巧,把括號序列轉化為01序列,左0右1,處理時比較方便
代碼:
#include<cstdio> #include<iostream> #include<cstring> using namespace std; int p[30]; int w[30]; int s[100]; int main() { int t,n,i,j,k,q; int sum1,sum2,head,rear,t1,t2,headw,rearw; scanf("%d",&t); while(t--) { sum1=0,sum2=0,head=0,rear=0; scanf("%d",&n); for(i=0;i<n;i++) { scanf("%d",&p[i]); if(sum1<p[i]) { for(j=0;j<p[i]-sum1;j++) s[rear++]=0; sum1=p[i]; } s[rear++]=1; sum2++; } rearw=headw=0; while(head!=rear) { t1=0,t2=0; if(s[head]==1) { t1++; if(s[head-1]==0) w[rearw++]=1; else { t1++; q=head-1; while(t1!=t2) { q--; if(s[q]==0) t2++; else t1++; } w[rearw++]=t1; } head++; } else head++; } for(k=0;k<rearw;k++) printf("%d%c",w[k],k==rearw-1?'\n':' '); } return 0; }