USACO: Longest Prefix



/*
 ID: tausiq11
 PROG: prefix
 LANG: C++
 */

// @BEGIN_OF_SOURCE_CODE

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <sstream>
#include <cmath>
#include <bitset>
#include <utility>
#include <set>
#include <numeric>
#include <ctime>

#define Inf 2147483647
#define Pi acos(-1.0)
#define N 200000 + 10
#define P 200 + 5
#define LL long long

inline LL Power(int b, int p) { LL ret = 1; for ( int i = 1; i <= p; i++ ) ret *= b; return ret; }
const int dr [] = {-1, -1, 0, 1, 1, 1, 0, -1};
const int dc [] = {0, 1, 1, 1, 0, -1, -1, -1};

#define F(i, a, b) for( int i = (a); i < (b); i++ )
#define Fs(i, sz) for( size_t i = 0; i < sz.size (); i++ )
#define Fe(i, x) for(typeof (x.begin()) i = x.begin(); i != x.end (); i++)
#define Set(a, s) memset(a, s, sizeof (a))
#define max(a, b)  (a < b ? b : a)
#define min(a, b)  (a > b ? b : a)


using namespace std;

char input [N];

char sequence [N];

char primitives [P] [10 + 2];

int maxi;

int primitivesSize [P];

int lenPrimitives = 0;

int main ()
{
    freopen ("prefix.in", "r", stdin);
    freopen ("prefix.out", "w", stdout);
    
    while ( scanf ("%s", input) && strcmp (input, ".") != 0 ) {
        
        strcpy (primitives [lenPrimitives], input);
            
        primitivesSize [lenPrimitives++] = (int) strlen (input);
        
    }
    
    strcpy(sequence, "");
    
    while ( scanf ("%s", input) != EOF ) {
        
        strcat(sequence, input);
    }

    bool isAvailable [N];

    Set(isAvailable, false);

    isAvailable [0] = true;

    int sequenceLength = strlen(sequence);

    for ( int i = 0; i < sequenceLength; i++ ) {

        if ( isAvailable [i]) {

            for ( int j = 0; j < lenPrimitives; j++ ) {
                if (strncmp (sequence + i, primitives [j], (size_t) primitivesSize[j]) == 0) {
                    maxi = max (maxi, i + primitivesSize[j]);
                    isAvailable [i + primitivesSize [j]] = true;
                }

            }
        }
    }
    
    printf ("%d\n", maxi);
    
    return 0;
}

Response:


USER: Shadow King [tausiq11]
TASK: prefix
LANG: C++

Compiling...
Compile: OK

Executing...
   Test 1: TEST OK [0.000 secs, 3832 KB]
   Test 2: TEST OK [0.000 secs, 3836 KB]
   Test 3: TEST OK [0.000 secs, 3828 KB]
   Test 4: TEST OK [0.003 secs, 3836 KB]
   Test 5: TEST OK [0.000 secs, 3832 KB]
   Test 6: TEST OK [0.581 secs, 3832 KB]

All tests OK.
Your program ('prefix') produced all correct answers!  This is your
submission #9 for this problem.  Congratulations!

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s