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| #include <cstdio>
#include <algorithm>
#include <cctype>
#include <cstring>
#include <queue>
#include <map>
using namespace std;
inline int read(int f = 1, int x = 0, char ch = ' ')
{
while(!isdigit(ch = getchar())) if(ch == '-') f = -1;
while(isdigit(ch)) x = x*10+ch-'0', ch = getchar();
return f*x;
}
const int N = 6e6+5, INF = 0x3f3f3f3f;
const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, 1, -1};
struct Edge
{
int next, to, w;
Edge(int next = 0, int to = 0, int w = 0): next(next), to(to), w(w) {};
}edge[N];
int tot = 1, head[N], s, t, n, m;
void _add(int x, int y, int z) { edge[++tot] = Edge(head[x], y, z); head[x] = tot; }
void add(int x, int y, int z) { _add(x, y, z); _add(y, x, 0); }
int d[N];
bool bfs()
{
memset(d, 0, sizeof(d));
queue<int> q; q.push(s); d[s] = 1;
while(q.size())
{
int x = q.front(); q.pop();
for(int i = head[x]; i; i = edge[i].next)
{
int y = edge[i].to, z = edge[i].w;
if(!z||d[y]) continue;
d[y] = d[x]+1; q.push(y);
if(y == t) return true;
}
}
return false;
}
int dinic(int x, int flow)
{
if(x == t) return flow;
int rest = flow, k;
for(int i = head[x]; i&&rest; i = edge[i].next)
{
int y = edge[i].to, z = edge[i].w;
if(!z||d[y] != d[x]+1) continue;
k = dinic(y, min(z, rest));
edge[i].w -= k; edge[i^1].w += k; rest -= k;
if(!k) d[y] = 0;
}
return flow-rest;
}
map<pair<int, int> , int> h;
int r, c, col[N], px[N], py[N], w[N];
void addpurple(int x)
{
int _x = px[x], _y = py[x];
for(int i = 0; i < 2; ++i)
{
int nx = _x+dx[i], ny = _y;
if(!h.count(make_pair(nx, ny))) continue;
int y = h[make_pair(nx, ny)];
if(col[y] == 3) add(x, y, min(w[x], w[y]));
}
}
void addyellow(int x)
{
int _x = px[x], _y = py[x];
add(s, x, w[x]);
for(int i = 0; i < 4; ++i)
{
int nx = _x+dx[i], ny = _y+dy[i];
if(!h.count(make_pair(nx, ny))) continue;
int y = h[make_pair(nx, ny)];
if(col[y] == 1) add(x, y, INF);
}
}
void addgreen(int x)
{
int _x = px[x], _y = py[x];
add(x, t, w[x]);
for(int i = 0; i < 4; ++i)
{
int nx = _x+dx[i], ny = _y+dy[i];
if(!h.count(make_pair(nx, ny))) continue;
int y = h[make_pair(nx, ny)];
if(col[y] == 3) add(y, x, INF);
}
}
int maxflow, flow;
int main()
{
c = read(), r = read(), n = read(); s = n+1; t = n+2;
for(int i = 1; i <= n; ++i)
{
px[i] = read(), py[i] = read(), w[i] = read();
h[make_pair(px[i], py[i])] = i;
}
for(int i = 1; i <= n; ++i)
{
int x = px[i], y = py[i];
if((x%4 == 1&&y%2 == 1)||(x%4 == 0&&y%2 == 0)) col[i] = 1;
if((x%4 == 1&&y%2 == 0)||(x%4 == 0&&y%2 == 1)) col[i] = 2;
if((x%4 == 2&&y%2 == 1)||(x%4 == 3&&y%2 == 0)) col[i] = 3;
if((x%4 == 2&&y%2 == 0)||(x%4 == 3&&y%2 == 1)) col[i] = 4;
}
for(int x = 1; x <= n; ++x)
{
if(col[x] == 1) addpurple(x);
else if(col[x] == 2) addyellow(x);
else if(col[x] == 4) addgreen(x);
}
while(bfs()) while(flow = dinic(s, INF)) maxflow += flow;
printf("%d\n", maxflow);
return 0;
}
|
