Codeforces 508 E. Arthur and Brackets

Codeforces 508 E. Arthur and Brackets

Codeforces 508 E. Arthur and Brackets

Question link:

 

Question:
There are n pairs of parentheses. in order, the length range of each pair of parentheses is given and a condition is output.
Restrictions:
1 <= n <= 600
Ideas:
Greedy: matches first.
To solve the issue of matching parentheses, consider whether the stack can be used.

 

 

C ++ Code

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/* Codeforces 508 E. Arthur and Brackets Question: There are n pairs of parentheses. in order, the length range of each pair of parentheses is given and a condition is output. Restrictions: 1 <= n <= 600 Ideas: Greedy: matches first. To solve the issue of matching parentheses, consider whether the stack can be used. */ # Include # Include Using namespace std; Const int n= 605; Int stk [N], top; Char ans [2 * N]; Int len = 0; Int pos [N], l [N], r [N]; Int main () { Int n; Int flag = 1; Scanf (% d, & n ); For (int I = 0; I <n; ++ I) { Scanf (% d, & l [I], & r [I]); If (flag = 0) continue; Stk [++ top] = I; Pos [I] = len; Ans [len ++] = '('; While (top> 0 & pos [stk [top] + l [stk [top] <= len) { If (pos [stk [top] + r [stk [top] <len) { Flag = 0; Break; } Else { Ans [len ++] = ')'; -- Top; } } } If (flag & top = 0) { Puts (ans ); } Else { Puts (IMPOSSIBLE ); } Return 0; }