Submission #175851

#	Time	Username	Problem	Language	Result	Execution time	Memory
175851		Ruxandra985	Match (CEOI16_match)	C++14	37 / 100	2050 ms	15368 KiB

match

#include <bits/stdc++.h>
#pragma GCC optimize "Ofast"
using namespace std;
int sp[30][100010];
char sol[100010] , s[100010];
int ok;
int stk[100010] , pre[30][100010];
int match (int st , int dr){
    int i , elem = 0;
    if (st > dr)
        return 1;
    for (i=0;i<'z' - 'a';++i){
        if (((sp[i][dr] - sp[i][st-1]) & 1) == 1)
            return 0;
    }

    for (i=st;i<=dr;++i){
        if (stk[elem] == s[i])
            elem--;
        else stk[++elem] = s[i];
    }
    return (elem == 0);

}
void solve (int st , int dr){
    int i;
    if (st > dr)
        return;
    if (!ok) /// nu mai are rost
        return;
    /// stii ca pe st pui ( , gaseste i match ul

    for (i = pre[s[st]][dr]; i >= st + 1 ; i = pre[s[st]][i-1]){
        if (match(st + 1 , i - 1) && match(i + 1 , dr))
            break;
    }
    if (i < st + 1){
        ok = 0;
        return;
    }
    else {
        sol[st] = '(';
        sol[i] = ')';
        solve(st + 1 , i - 1);
        solve (i + 1 , dr);
    }
}
int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    int n , i;
    fgets (s+1 , 100010 , fin);

    n = 0;
    while ( 'a' <= s[n+1] && s[n+1] <= 'z' ){
        n++;
        s[n]-='a';

        for (i=0;i<='z'-'a';++i){
            sp[i][n] = sp[i][n-1] + (s[n] == i);
            if (i == s[n])
                pre[i][n] = n;
            else pre[i][n] = pre[i][n-1];
        }
    }
    stk[0] = -1;
    ok = 1;
    solve (1 , n);
    if (ok == 0){
        fprintf (fout,"-1");
    }
    else {
        fputs (sol+1,fout);
    }
    return 0;
}

Compilation message (stderr)

match.cpp: In function 'void solve(int, int)':
match.cpp:33:23: warning: array subscript has type 'char' [-Wchar-subscripts]
     for (i = pre[s[st]][dr]; i >= st + 1 ; i = pre[s[st]][i-1]){
                       ^
match.cpp:33:57: warning: array subscript has type 'char' [-Wchar-subscripts]
     for (i = pre[s[st]][dr]; i >= st + 1 ; i = pre[s[st]][i-1]){
                                                         ^
match.cpp: In function 'int main()':
match.cpp:53:11: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     fgets (s+1 , 100010 , fin);
     ~~~~~~^~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/stdio.h:936:0,
                 from /usr/include/c++/7/cstdio:42,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:46,
                 from match.cpp:1:
In function 'char* fgets(char*, int, FILE*)',
    inlined from 'int main()' at match.cpp:53:11:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:261:58: warning: call to '__fgets_chk_warn' declared with attribute warning: fgets called with bigger size than length of destination buffer
  return __fgets_chk_warn (__s, __bos (__s), __n, __stream);
                                                          ^

• Subtask 1: 10 / 10
• Subtask 2: 27 / 27
• Subtask 3: 0 / 63