链接:
Parencodings
Time Limit: 1000MS | Memory Limit: 10000K | |
Total Submissions: 17044 | Accepted: 10199 |
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
Source
题意:
先看题目样例中给出的括号序列 S 注意到它有 6 个右括号
而下面的两个数字序列 P 和 W 都含有 6 个数字,而且都写在这右边6个括号下面
再仔细看序列 P 代表的是从左到右,每一个右括号前面的左括号的个数
平时生活中括号都是一对对存在的
W序列代表的是与当前右括号匹配的最近的左括号编号
【这个编号是按照离开当前需要匹配的右边括号的,左边括号个数计算的】
题目给了你序列 P 要你输出序列 W ,简单模拟一下就好了
而下面的两个数字序列 P 和 W 都含有 6 个数字,而且都写在这右边6个括号下面
再仔细看序列 P 代表的是从左到右,每一个右括号前面的左括号的个数
平时生活中括号都是一对对存在的
W序列代表的是与当前右括号匹配的最近的左括号编号
【这个编号是按照离开当前需要匹配的右边括号的,左边括号个数计算的】
题目给了你序列 P 要你输出序列 W ,简单模拟一下就好了
算法:
简单模拟
思路:
用一个数组标记即可,左括号标记为 0,右括号标记为 1
同时再用一个 vis[] 数组标记已经被匹配过了的左边括号
同时再用一个 vis[] 数组标记已经被匹配过了的左边括号
/** Accepted 180K 0MS C++ 1586B 题意:先看题目样例中给出的括号序列 S 注意到它有 6 个右括号 而下面的两个数字序列 P 和 W 都含有 6 个数字,而且都写在这右边6个括号下面 再仔细看序列 P 代表的是从左到右,每一个右括号前面的左括号的个数 平时生活中括号都是一对对存在的 W序列代表的是与当前右括号匹配的最近的左括号编号 【这个编号是按照离开当前需要匹配的右边括号的,左边括号个数计算的】 题目给了你序列 P 要你输出序列 W ,简单模拟一下就好了 算法:简单模拟 思路:用一个数组标记即可,左括号标记为 0,右括号标记为 1 同时再用一个 vis[] 数组标记已经被匹配过了的左边括号 */ #include<stdio.h> #include<string.h> const int maxn = 2000; int a[maxn]; //记录括号是左边还是右边 int vis[maxn]; // 标记是否被匹配 int main() { int T; int n; scanf("%d", &T); while(T--) { scanf("%d", &n); memset(vis, 0, sizeof(vis)); //初始化清空 memset(a, 0, sizeof(a)); int x; int t = 0; //记录当下左括号数目 int index = 1; //记录当前括号下标 int j; for(int i = 0; i < n; i++) { scanf("%d", &x); //每次输入一个右边括号,同时补全它左边括号的数目 if(x > t) { int tmp = x-t; //记录当前左边 t = x; while(tmp--) { a[index++] = 0; //补全左边括号 } } a[index++] = 1; //记录当前右边括号 } int flag = 0; int num = index; // 总的括号数目 //for(int i = 1; i < num; i++) printf("%d ", a[i]); printf(" "); for(int i = 1; i < num; i++) // 从前往后遍历 ) { if(a[i] == 1) // ) { flag = 0; int ans = 0; for(int j = i-1; j >= 1; j--) // 从后往前匹配 { if(flag == 1) break; if(a[j] == 0 && vis[j] && flag == 0) { ans++; } else if(a[j] == 0 && !vis[j]) { ans++; vis[j] = 1; printf("%d ", ans); flag = 1; break; } } } } printf(" "); } return 0; }