求最大流最小费用随机生成节点具体例子matlab完整代码,包含算法的具体代码
时间: 2023-07-10 09:04:52 浏览: 46
以下是最大流最小费用问题的随机生成节点的Matlab完整代码,包括算法的具体代码:
```
function [flow, cost] = max_flow_min_cost(n, m, s, t, cmax)
% n: 节点数
% m: 边数
% s: 起点
% t: 终点
% cmax: 最大边权值
% 随机生成图
G = sparse(n, n);
for i = 1:m
u = randi(n-1);
v = randi(n-u) + u;
c = randi(cmax);
G(u, v) = G(u, v) + c;
end
% 最大流最小费用算法
flow = 0;
cost = 0;
while true
[f, p, d] = spfa(G, s, t);
if f == 0
break;
end
flow = flow + f;
cost = cost + f * d(t);
v = t;
while v ~= s
u = p(v);
G(u, v) = G(u, v) - f;
G(v, u) = G(v, u) + f;
v = u;
end
end
function [f, p, d] = spfa(G, s, t)
% SPFA算法求最短路
n = size(G, 1);
f = inf(n, 1); % 到源点的距离
p = zeros(n, 1); % 前驱节点
d = zeros(n, 1); % 边权值
vis = false(n, 1); % 是否在队列中
f(s) = 0;
vis(s) = true;
q = Queue();
q.push(s);
while ~q.empty()
u = q.front();
q.pop();
vis(u) = false;
for v = 1:n
if G(u, v) > 0 && f(v) > f(u) + d(u) - d(v)
f(v) = f(u) + d(u) - d(v);
p(v) = u;
if ~vis(v)
vis(v) = true;
q.push(v);
end
end
end
end
if f(t) == inf
f = 0;
return;
end
f = 1;
while f > 0
delta = inf;
v = t;
while v ~= s
u = p(v);
delta = min(delta, G(u, v));
v = u;
end
v = t;
while v ~= s
u = p(v);
G(u, v) = G(u, v) - delta;
G(v, u) = G(v, u) + delta;
v = u;
end
f = f - delta;
end
d = f;
```
这段代码会随机生成一个有n个节点,m条边的图,每条边的权值在1到cmax之间随机生成。然后使用SPFA算法求解最大流最小费用问题。