POJ3126 Prime Path 素数

#ifndef HEAD
#include <stdio.h>
#include <vector>
#include <math.h>
#include <string.h>
#include <string>
#include <iostream>
#include <queue>
#include <list>
#include <algorithm>
#include <stack>
#include <map>

using namespace std;
#endif // !HEAD

#ifndef QUADMEMSET
inline void QuadMemSet(void* dst, int iSize, int value)
{
iSize = iSize / 4;
int* newDst = (int*)dst;
#ifdef WIN32
__asm
{
mov edi, dst
mov ecx, iSize
mov eax, value
rep stosd
}
#else
for (int i = 0; i < iSize; i++)
{
newDst[i] = value;

}
#endif
}
#endif

struct EDGE
{
int from;
int to;
int cost;
EDGE* next;
};

int Dij(int s, int to, vector<EDGE*> &head,int N)
{
vector<int> visited;
visited.resize(N, 0);
vector<int> res;
res.resize(N, 10000000);
res[s] = 0;
//int t = s;
while (true)
{
int v = -1;
for (int t = 0; t<N; t++)
{
if (visited[t] == 0 && (v == -1 || res[v] > res[t]))
{
v = t;
}
}
if (v == -1 || res[v] >= 10000000)
{
break;
}
visited[v] = 1;
for (EDGE* p = head[v]; p; p = p->next)
{
if (visited[p->to] == 0)
{
res[p->to] = min(res[p->to], res[v] + p->cost);
}
}
}
return res[to];
}
EDGE edges[20000];
int main()
{
int is_prime[101];
int ab_isprime[10000];
memset(is_prime, 1, sizeof(is_prime));
memset(ab_isprime, 1, sizeof(ab_isprime));
is_prime[0] = is_prime[1] = 0;
for (int i = 2; i * i < 10001;i++)
{
if (is_prime[i])
{
for (int j = 2 * i; j < 101;j += i)
{
is_prime[j] = 0;
}
for (int j = max(2, (1000 + i - 1) / i) * i; j < 10000; j += i)
{
ab_isprime[j] = 0;
}
}
}
vector<int> abPrimes;
map<int, int> mapIndex;
for (int i = 1000; i < 10000;i++)
{
if (ab_isprime[i])
{
abPrimes.push_back(i);
mapIndex[i] = abPrimes.size() - 1;
}
}

vector<EDGE*> head;
head.resize(abPrimes.size(), NULL);
int count = 0;
for (int i = 0; i < abPrimes.size();i++)
{
for (int j = 0; j < abPrimes.size();j++)
{
int countofzero = 0;
int div = 1;
while (div <= 1000)
{
if ((abPrimes[i]/div) % 10 - abPrimes[j] / div % 10 == 0)
{
countofzero++;
}
div *= 10;
}
if (i == j)
{
continue;
}
if (countofzero == 3)
{
EDGE edge;
edge.from = i;
edge.to = j;
edge.cost = 1;
edge.next = head[i];
EDGE invedge = edge;
invedge.from = j;
invedge.to = i;
edges[count] = edge;;
head[i] = &edges[count++];
invedge.next = head[j];
edges[count] = invedge;
head[j] = &edges[count++];
}
}
}
#ifdef _DEBUG
freopen("d:\\in.txt", "r", stdin);
#endif
int N;
scanf("%d\n", &N);
for (int i = 0; i < N;i++)
{
int a, b;
scanf("%d %d\n", &a, &b);
if (a == b)
{
printf("0\n");
}
else
{
printf("%d\n", Dij(mapIndex[a], mapIndex[b], head, abPrimes.size()));
}
}
return 0;
}