求两个字符串的编辑距离

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// 求两个字符串的编辑距离 int editMinDistance( const char *s1, const char *s2 )    {        int dist = 0;        if( NULL == s1 && NULL == s2 )        {            return dist;        }        if( NULL == s1 )        {            dist = strlen(s2);            return dist;        }        else if( NULL == s2 )        {            dist = strlen(s1);            return dist;        }        int len1 = strlen(s1);        int len2 = strlen(s2);        if( 0 == len1 && 0 == len2 )        {            dist = 0;            return dist;        }        else if( 0 == len1 )        {            return len2;        }        else if( 0 == len2 )        {            return len1;        }        if( s1[0] == s2[0] )        {            dist = editMinDistance( s1 + 1, s2 + 1 );        }        else         {            int d1 = 1 + editMinDistance( s1 + 1, s2 + 1 );            int d2 = 1 + editMinDistance( s1, s2 + 1 );            int d3 = 1 + editMinDistance( s1 + 1, s2 );            int max = d1 > d2 ? d2 : d1;            dist = max > d3 ? d3 : max;        }        return dist;    }=================================================#include <iostream>#include <string.h>#include <stdio.h>#include <stdlib.h>using namespace std;int minValue( int v1, int v2, int v3 ){    if( v1 <= v2 && v1 <= v3 )    {        return v1;    }    if( v2 <= v1 && v2 <= v3 )    {        return v2;    }    if( v3 <= v1 && v3 <= v2 )    {        return v3;    }}// 求两个字符串的编辑距离// 编辑距离，又称Levenshtein距离，是指两个字串之间，由一个转成另一个所需的最少编辑操作次数。许可的编辑操作包括将一个字符替换成另一个字符，插入一个字符，删除一个字符。// From: 《王道-程序员求职宝典P192》int calStringDistance( string X, string Y ){    int result = 0;    int len1 = X.length();    int len2 = Y.length();    if( 0 == len1 )    {        result = len2;        return result;    }       if( 0 == len2 )    {        result = len1;        return result;    }    int **p = new int *[ len1 + 1 ];    for( int i = 0; i < len1 + 1; ++i )    {        p[i] = new int[ len2 + 1 ];    }    for( int i = 0; i <= len1; ++i )    {        p[i][len2] = len1 - i;    }    for( int i = 0; i <= len2; ++i )    {        p[len1][i] = len2 - i;    }    p[len1][len2] = 0;    for( int i = len1 - 1; i >= 0; --i )    {        for( int j = len2 - 1; j >= 0; --j )        {            if( X[i] == Y[j] )            {                p[i][j] = p[ i + 1 ][ j + 1 ];            }            else            {                int v1 = p[ i + 1 ][j];                int v2 = p[i][ j + 1 ];                int v3 = p[ i + 1 ][ j + 1 ];                p[i][j] = minValue( v1, v2, v3 ) + 1;            }        }    }    result = p[0][0];    for( int i = 0; i < len1 + 1; ++i )    {        delete []p[i];    }    delete []p;    return result;}const int SIZE = 100;int cnt1 = 0;int dist[SIZE][SIZE];int calStringDistance1( string X, string Y, int i, int j ){    int result = 0;    int len1 = X.length();    int len2 = Y.length();    if( i < 0 || j < 0 || i > len1 || j > len2 )    {        cout << "calStringDistance1 func: err -1, i < 0 || j < 0 || i > len1 || j > len2" << endl;        result = -1;        return result;          }    if( i == len1 )    {        dist[i][j] = len2 - j;        result = dist[i][j];        return result;     }    if( j == len2 )    {        dist[i][j] = len1 - i;        result = dist[i][j];        return result;    }    if( dist[i][j] != -1 ) //备忘录解法    {        cnt1 = cnt1 + 1;            return dist[i][j];    }    if( X[i] == Y[j] )    {        dist[i][j] = calStringDistance1( X, Y, i + 1, j + 1 );    }    else    {        int v1 = calStringDistance1( X, Y, i + 1, j );         int v2 = calStringDistance1( X, Y, i, j + 1 );         int v3 = calStringDistance1( X, Y, i + 1, j + 1 );         dist[i][j] = minValue( v1, v2, v3 ) + 1;     }    result = dist[i][j];    return result;}int main(){    int ret = 0;    for( int i = 0; i < SIZE; ++i )    {        for( int j = 0; j < SIZE; ++j )        {            dist[i][j] = -1;        }    }    //cout << calStringDistance( "ab", "c" ) << endl;    cout << calStringDistance( "awrtg234sfgtsf2r24sdgddg5sgsagadgb", "csgqsdf4tdgssafsfsafsfsgsddhdfffffffffsfsfwetxgasd" ) << endl; // 39    cout << calStringDistance1( "awrtg234sfgtsf2r24sdgddg5sgsagadgb", "csgqsdf4tdgssafsfsafsfsgsddhdfffffffffsfsfwetxgasd", 0, 0 ) << endl; // 39    cout << cnt1 << endl; // 2840    return ret;}/*39392840*/
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