eddis.h

#ifndef EDDIS_H
#define EDDIS_H

#include <cassert>
#include <string>
#include <vector>
using namespace std;


inline size_t min(size_t x, size_t y, size_t z)
{
    if (x < y)
        return x < z ? x : z;
    else
        return y < z ? y : z;
}

size_t editDist(const string& A, const string& B)
{
    size_t NA = A.size();
    size_t NB = B.size();

    vector<vector<size_t>> M(NA + 1, vector<size_t>(NB + 1));

    for (size_t a = 0; a <= NA; ++a)
        M[a][0] = a;

    for (size_t b = 0; b <= NB; ++b)
        M[0][b] = b;

    for (size_t a = 1; a <= NA; ++a)
        for (size_t b = 1; b <= NB; ++b)
        {
            size_t x = M[a-1][b] + 1;
            size_t y = M[a][b-1] + 1;
            size_t z = M[a-1][b-1] + (A[a-1] == B[b-1] ? 0 : 1);
            M[a][b] = min(x,y,z);
        }

    return M[A.size()][B.size()];
}

#endif // EDDIS_H