MODEL: SETS: CUST /1..20/; CENTER /1..5/; ENDSETS DATA: CUSTOMER_X_COORD(CUST) = 2 3 8 7 6 5 1 9 6 4 5 3 1 7 2 9 8 4 6 10; CUSTOMER_Y_COORD(CUST) = 5 1 2 3 4 7 10 2 6 9 3 1 4 5 7 10 4 5 8 9; CENTER_X_COORD(CENTER) = 1 3 6 8 10; CENTER_Y_COORD(CENTER) = 1 3 5 7 9; CAPACITY(CUST) = 20 10 30 15 5 25 20 10 15 30 10 20 25 5 15 30 20 10 25 5; VEHICLE_NUMBER(CENTER) = 2 3 1 2 1; ENDDATA DataRef: CUSTOMER_X_COORD, CUSTOMER_Y_COORD, CENTER_X_COORD, CENTER_Y_COORD, CAPACITY, VEHICLE_NUMBER; EndDataRef @Table COST_MATRIX(CUST, CENTER) = @SQRT((CUSTOMER_X_COORD(CUST)-CENTER_X_COORD(CENTER))^2 + (CUSTOMER_Y_COORD(CUST)-CENTER_Y_COORD(CENTER))^2); VARIABLES: X(CUST, CENTER), Binary; Y(CENTER),Integer; ENDVARIABLES Minimize： Total_Cost : = @sum((i, j, k | k <> j), X(i,j,k) * COST_MATRIX(i,j)); Subject to: Constraint1(i in CUST): @sum(X(i,j,k) * CAPACITY(i) | j in CENTER, k in CENTER) <= sum(Y(j) * VEHICLE_NUMBER(j) | j in CENTER); Constraint2(j in CENTER): @sum(Y(j)) >= 1; Constraint3(i in CUST): @sum(X(i,j,k) | j in CENTER, k in CENTER) = 1; Constraint4(i in CUST, j in CENTER): @sum(X(i,j,k) | k in CENTER) <= Y(j); End这段代码放在lingo里无法输出结果，帮我检查并改正一下

这段代码并不是 Lingo 语言，而是 AMPL 语言。你需要使用 AMPL 软件来运行这段代码，而不是 Lingo。

如果你已经在 AMPL 中运行了这段代码，但是无法输出结果，可能是因为缺少输出语句。你可以在 Minimize 语句后面添加一个 print 语句，例如：

Minimize Total_Cost : = @sum((i, j, k | k <> j), X(i,j,k) * COST_MATRIX(i,j));
print Total_Cost;

这样就可以输出最小化总成本的结果了。同样地，你也可以在 Subject to 语句后面添加 print 语句，输出约束条件的结果。