C++博客-purplest-随笔分类-String Algorithm

poj 1204 Word Puzzles

purplest — Sun, 11 Sep 2011 15:35:00 GMT

AC自动机+搜索，直接trie也能过

#include <stdio.h>
#include <string.h>

char str[1010][1010], temstr[1010];
int r, c, n, point;
int queue[501000];
int div[8][2]={{-1, 0}, {-1, 1}, {0, 1}, {1, 1}, {1, 0}, {1, -1}, {0, -1}, {-1, -1}};

struct P
{
    int child[27];
    int len, fail, id, num;
}node[501000];

struct ANS
{
    int x, y;
    char c;
}ans[1010];

void insert(int id)
{
    int p = 0, len= strlen(temstr), t;
    for ( int i = 0 ; temstr[i] ; i++ )
    {
        t= temstr[i]-'A';
        if ( !node[p].child[t] )
            node[p].child[t]= point++;
        p= node[p].child[t];
    }
    node[p].num++;
    node[p].id=id;
    node[p].len=len;
}

void init()
{
    memset(node, 0, sizeof(node));
    point= 1;
}

void buildAC()
{
    int rear=-1, front=0, i, k;
    queue[0]= 0;
    node[0].fail= -1;
    while ( rear < front )
    {
        int now= queue[++rear];
        for ( i = 0 ; i < 26 ; i++ )
        {
            int t= node[now].child[i];
            if ( !t ) continue;
            for ( k = node[now].fail ; k != -1 ; k= node[k].fail )
                if (node[k].child[i])
                {
                    node[t].fail=node[k].child[i];
                    break;
                }
            if ( k == -1 )
                node[t].fail=0;
            queue[++front]= t;
        }
    }
}

void find(int x, int y, int k)
{
    int i = x, j= y, p= 0;
    while (  0 <= i && i < r && 0 <= j && j < c )
    {
        int ch= str[i][j]-'A';
        if (node[p].child[ch])
        {
            p= node[p].child[ch];
            if ( node[p].num>0 )
            {
                int id= node[p].id;
                ans[id].x= i-(node[p].len-1)*div[k][0];
                ans[id].y= j-(node[p].len-1)*div[k][1];
                ans[id].c= k+'A';
                node[p].num= 0;
            }
            i+=div[k][0];
            j+=div[k][1];
        }
        else if(p)
        {
            p= node[p].fail;
            if (node[p].num>0)
            {
                int id= node[p].id;
                ans[id].x= i-(node[p].len-1)*div[k][0];
                ans[id].y= j-(node[p].len-1)*div[k][1];
                ans[id].c= k+'A';
                node[p].num= 0;
            }
        }
        else
        {
            i+=div[k][0];
            j+=div[k][1];
        }
    }
}

void get()
{
    int i;
    for ( i = 0 ; i < c ; i++ )
    {
        find(r-1, i, 7);
        find(r-1, i, 0);
        find(r-1, i, 1);
        find(0, i, 3);
        find(0, i, 4);
        find(0, i, 5);
    }
    for ( i = 0 ; i < r ; i++ )
    {
        find(i, 0, 1);
        find(i, 0, 2);
        find(i, 0, 3);
        find(i, c-1, 5);
        find(i, c-1, 6);
        find(i, c-1, 7);
    }
}

int main()
{
    scanf("%d%d%d", &r, &c, &n);
    int i;
    init();
    for ( i = 0 ; i < r ; i++ )
        scanf("%s", str[i]);
    for ( i = 0 ; i < n ; i++ )
    {
        scanf("%s", temstr);
        insert(i+1);
    }
    buildAC();
    get();
    for ( int i = 0 ; i < n ; i++ )
        printf("%d %d %c\n", ans[i+1].x, ans[i+1].y, ans[i+1].c);
    return 0;
}

purplest 2011-09-11 23:35 发表评论

poj 1782 Run Length Encoding

purplest — Tue, 23 Aug 2011 16:42:00 GMT

模拟题，trick很多。。。

#include <stdio.h>
#include <string.h>

char str[1000];

int main()
{
    memset(str, 0, sizeof(str));
    while ( !feof(stdin) )
    {
        gets(str);
        if (!str[0])
        {
            putchar(10);
            continue;
        }
        int i, j;
        for ( i = 0 ; str[i] ; i++ )
        {
            if (str[i] == str[i+1])
            {
                for ( j = i ; str[i] == str[i+1] && (i-j) < 8 ; i++ );
                printf("%d%c", i-j+1, str[i]);
            }
            else
            {
                printf("1");
                for ( j = i ; str[i] != str[i+1] && str[i] ; i++ )
                {
                    if ('1' == str[i]) printf("1");
                    printf("%c", str[i]);
                }
                printf("1");
                if ( str[i] == str[i+1]) i--;
            }
        }
        putchar(10);
        memset(str, 0, sizeof(str));
    }
    return 0;
}

purplest 2011-08-24 00:42 发表评论

Poj 1631 Bridging signals

purplest — Sun, 31 Jul 2011 11:51:00 GMT

果的LIS，直接贴代码

#include <stdio.h>

int a[40000], b[40000], n, i, j, sum;

void LIS()
{
    int left= 0, right= sum-1, mid;

    if(0 == i)
    {
        b[0]=a[i];
    }
    else
    {
        while(left <= right)
        {
            mid= (left + right)>>1;
            if(b[mid] > a[i])
            {
                right= mid-1;
            }
            else
            {
                left= mid+1;
            }
        }
        b[left]= a[i];
        if(left >= sum)
        {
            sum++;
        }
    }
}

int main ()
{
    int m, j;
    scanf("%d", &m);
    for(j= 0; j < m; j++)
    {
        scanf("%d", &n);
        sum= 1;
        for(i= 0; i < n; i++)
        {
            scanf("%d", a+i);
            LIS();
        }
        printf("%d\n", sum);
    }
    return 0;
}

purplest 2011-07-31 19:51 发表评论