学步园

HDU_2813

    为了避免读入数据时判重的超时，可以采用哈希去处理，然后再把不重复的人名取出来看做一个点，构图后再用KM算法求二分图最优匹配即可。

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define MAXD 210
#define MAXM 40010
#define INF 1000000000
#define HASH 10007
int headL[HASH], nextL[MAXM], headC[HASH], nextC[MAXM];
int N, M, K, G[MAXD][MAXD], yM[MAXD], MAX;
int A[MAXD], B[MAXD], slack[MAXD];
int visx[MAXD], visy[MAXD];
char L[MAXD][30], C[MAXD][30], KL[MAXM][30], KC[MAXM][30];
int w[MAXM], Lr[MAXD], Cr[MAXD];
int hash(char *str)
{
int seed = 131, v = 0;
while(*str)
        v = v * seed + *(str ++);
return (v & 0x7FFFFFFF) % HASH;
}
int cmp1(const void *_p, const void *_q)
{
int *p = (int *)_p;
int *q = (int *)_q;
return strcmp(L[*p], L[*q]);
}
int cmp2(const void *_p, const void *_q)
{
int *p = (int *)_p;
int *q = (int *)_q;
return strcmp(C[*p], C[*q]);
}
void insert_L(int s)
{
int i, h;
    h = hash(KL[s]);
for(i = headL[h]; i != -1; i = nextL[i])
if(strcmp(KL[i], KL[s]) == 0)
break;
if(i == -1)
    {
        nextL[s] = headL[h];
        headL[h] = s;
    }
}
void insert_C(int s)
{
int i, h;
    h = hash(KC[s]);
for(i = headC[h]; i != -1; i = nextC[i])
if(strcmp(KC[i], KC[s]) == 0)
break;
if(i == -1)
    {
        nextC[s] = headC[h];
        headC[h] = s;
    }
}
int search_L(char *str)
{
int mid, left, right, k;
    left = 0;
    right = N;
for(;;)
    {
        mid = (left + right) / 2;
        k = strcmp(str, L[Lr[mid]]);
if(k == 0)
break;
else if(k > 0)
            left = mid;
else
            right = mid;
    }
return mid;
}
int search_C(char *str)
{
int mid, left, right, k;
    left = 0;
    right = M;
for(;;)
    {
        mid = (left + right) / 2;
        k = strcmp(str, C[Cr[mid]]);
if(k == 0)
break;
else if(k > 0)
            left = mid;
else
            right = mid;
    }
return mid;
}
void init()
{
int i, j, k, u, v, nL, nC;
    MAX = 0;
    memset(headL, -1, sizeof(headL));
    memset(headC, -1, sizeof(headC));
for(i = 0; i < K; i ++)
    {
        scanf("%s%s%d", KL[i], KC[i], &w[i]);
if(w[i] > MAX)
            MAX = w[i];
        insert_L(i);
        insert_C(i);
    }
    MAX += 100;
    nL = nC = 0;
for(i = 0; i < HASH; i ++)
    {
if(headL[i] != -1)
        {
for(j = headL[i]; j != -1; j = nextL[j])
                strcpy(L[nL ++], KL[j]);
        }
if(headC[i] != -1)
        {
for(j = headC[i]; j != -1; j = nextC[j])
                strcpy(C[nC ++], KC[j]);
        }
    }
for(i = 0; i < N; i ++)
        Lr[i] = i;
for(i = 0; i < M; i ++)
        Cr[i] = i;
    qsort(Lr, N, sizeof(Lr[0]), cmp1);
    qsort(Cr, M, sizeof(Cr[0]), cmp2);
    memset(G, 0, sizeof(G));
for(i = 0; i < K; i ++)
    {
        u = search_L(KL[i]);
        v = search_C(KC[i]);
if(MAX - w[i] > G[u][v])
            G[u][v] = MAX - w[i];
    }
}
int searchpath(int u)
{
int v, temp;
    visx[u] = 1;
for(v = 0; v < M; 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[v])
                slack[v] = temp;
        }
return 0;
}
void KM()
{
int i, j, temp, u;
for(i = 0; i < N; i ++)
    {
        A[i] = 0;
for(j = 0; j < M; 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 < N; u ++)
    {
for(i = 0; i < M; i ++)
            slack[i] = INF;
for(;;)
        {
            memset(visx, 0, sizeof(visx));
            memset(visy, 0, sizeof(visy));
if(searchpath(u))
break;
int d = INF;
for(i = 0; i < M; i ++)
if(slack[i] < d)
                    d = slack[i];
for(i = 0; i < N; i ++)
if(visx[i])
                    A[i] -= d;
for(i = 0; i < M; i ++)
if(visy[i])
                    B[i] += d;
        }
    }
}
void printresult()
{
int i, res = 0;
for(i = 0; i < M; i ++)
if(yM[i] != -1)
            res += MAX - G[yM[i]][i];
    printf("%d\n", res);
}
int main()
{
while(scanf("%d%d%d", &N, &M, &K) == 3)
    {
        init();
        KM();
        printresult();
    }
return 0;
}