POJ 2192 Zipper

判断a的前i个字母和b的前j个字母能否构成 c的前 i + j个字母，递推，注意数组开大些，205居然会wa。

/*Accepted 220K 0MS C++ 911B 2012-04-22 10:42:42 */

#include<cstdio>
#include<cstring>
#include<cstdlib>
#define MAXN 255

bool match[MAXN][MAXN];
char a[MAXN], b[MAXN], c[MAXN << 1];
int la, lb, lc;

void dp()
{
    int i, j;
    la = strlen( a + 1), lb = strlen( b + 1), lc = strlen( c + 1);
    if( a[la] == c[lc] || b[lb] == c[lc])
    {
        match[0][0] = true;
        for( i = 0; a[i]; ++ i)
            for( j = 0; b[j]; ++ j)
            {
                match[i][j] = i | j ? false : true;
                int k = i + j;
                if( i > 0 && a[i] == c[k])
                    match[i][j] |= match[i - 1][j];
                if( j > 0 && b[j] == c[k])
                    match[i][j] |= match[i][j - 1];
            }
    }
    else match[la][lb] = false;
}

int main()
{
    int T;
    scanf( "%d", &T);
    for( int t = 1; t <= T; t ++)
    {
        a[0] = b[0] = c[0] = '0';
        scanf( "%s%s%s", a + 1, b + 1, c + 1);
        dp();
        printf( "Data set %d: ", t);
        if( match[la][lb]) printf( "yes\n");
        else printf( "no\n");
    }
    return 0;
}