s-t最大流问题AMPL代码

最大流问题可做为最小费用流问题的特例，当然可直接借用最小费用问题的AMPL代码，这里稍作修改给出一个更简洁些的版本。

option randseed 1;param N >=2 integer;param density >0,<1 :=20/N;set cities:=1..N;set links:=setof{i in 1..ceil(N*N*density)} (ceil(N*Uniform01()),ceil(N*Uniform01()));param cap{links} := ceil(10+980*Uniform01());param s:=1;param t:=N;node nodes{i in cities};arc F_In>=0, to nodes[s];arc F_Out>=0, from nodes[t];arc flow{(i,j) in links} >=0 <= cap[i,j]    from nodes[i] to nodes[j];maximize mfv: F_In;data;param N:=10000;option solver cplex;solve;display mfv;