HDU 3718 Similarity

HDU_3718

First, we need to convert the characters in the string into the number of [0, k-1] with the same meaning, and then scan the array sequentially, we can get the maximum value of various matching between the two sets of numbers, this completes the graph creation.

Then use the KM algorithm to find the optimal match.

#include<stdio.h>
#include<string.h>
#define MAXD 30
#define MAXN 10010
#define INF 1000000000
char a[MAXN][5], b[MAXN][5];
int visa[MAXN], visb[MAXN], x[MAXN], y[MAXN];
int G[MAXD][MAXD], yM[MAXD], N, K, M;
int A[MAXD], B[MAXD], slack;
int visx[MAXD], visy[MAXD];
void init()
{
int i, j, k;
for(i = 0; i < N; i ++)
        scanf("%s", a[i]);
    memset(visa, 0, sizeof(visa));
    k = 0;
for(i = 0; i < N; i ++)
if(!visa[i])
        {
for(j = i; j < N; j ++)
if(a[j][0] == a[i][0])
                {
                    visa[j] = 1;
                    x[j] = k;
                }
            k ++;
        }
}
void initM()
{
int i, j, k;
for(i = 0; i < N; i ++)
        scanf("%s", b[i]);
    memset(visb, 0, sizeof(visb));
    k = 0;
for(i = 0; i < N; i ++)
if(!visb[i])
        {
for(j = i; j < N ; j ++)
if(b[j][0] == b[i][0])
                {
                    visb[j] = 1;
                    y[j] = k;
                }
            k ++;
        }
    memset(G, 0, sizeof(G));
for(i = 0; i < N; i ++)
        G[x[i]][y[i]] ++;
}
int searchpath(int u)
{
int v, temp;
    visx[u] = 1;
for(v = 0; v < K; v ++)
if(!visy[v])
        {
            temp = A[u] + B[v] - G[u][v];
if(temp == 0)
            {
                visy[v] = 1;
if(yM[v] == -1 || searchpath(yM[v]))
                {
                    yM[v] = u;
return 1;
                }
            }
else if(temp < slack)
                slack = temp;
        }
return 0;
}
void KM()
{
int i, j, u;
for(i = 0; i < K; i ++)
    {
        A[i] = 0;
for(j = 0; j < K; j ++)
if(G[i][j] > A[i])
                A[i] = G[i][j];
    }
    memset(B, 0, sizeof(B));
    memset(yM, -1, sizeof(yM));
for(u = 0; u < K; u ++)
for(;;)
        {
            memset(visx, 0, sizeof(visx));
            memset(visy, 0, sizeof(visy));
            slack = INF;
if(searchpath(u))
break;
for(i = 0; i < K; i ++)
            {
if(visx[i])
                    A[i] -= slack;
if(visy[i])
                    B[i] += slack;
            }
        }
}
void printresult()
{
int i, res =0;
for(i = 0 ; i < K; i ++)
        res += G[yM[i]][i];
    printf("%.4f\n", (double)res / N);
}
int main()
{
int i, T;
    scanf("%d", &T);
while(T --)
    {
        scanf("%d%d%d", &N, &K, &M);
        init();
for(i = 0; i < M; i ++)
        {
            initM();
            KM();
            printresult();
        }
    }
return 0;
}