lingo tsp 错误代码 11 哪里错了啊

lingo tsp 错误代码 11 哪里错了啊
MODEL:
SETS:
CITY / 1..20/:U;
LINK( CITY,CITY):DIST,X;
ENDSETS
DATA:
dist=0 9.7 12.2 7.8 10.4 7.6 4.6 12.8 10 11.2 10.2 16.1 9.8 10.7 17.2 14.8 9.5 11.8 7.4
5.1 0 10.5 6.1 8.9 5.2 9.4 3 5.7 2.8 8.3 7.8 2.9 1.2 14.9 3.6 0.7 3.4 3.1
2.3 3.7 0 3.6 1.9 6 15.5 11.1 15.6 8.6 17.8 9.1 13.2 10.1 5.2 10.9 11 9.2 8.4
2.6x053.2x054x050x053.5x050.7x0510.3x057.8x0510.6x055.3x0512.6x058.9x058.3x056.1x0510.2x058.7x056.3x055.9x053.2
3.6x057.5x054.1x056x050x054.2x0513.7x0510x0513.9x057.4x0516.1x059x0511.6x058.8x056.9x0510.2x059.4x058x056.7
15x0513.1x0513x0515.3x0513.6x050x058.9x057.2x059.8x054.9x0511.9x058.7x057.6x055.5x0510.9x058.3x055.6x055.5x052.6
1.3x053.6x052.4x051.8x054.2x0514.1x050x0512.4x057.1x0511.7x056.3x0517.1x058.1x0510.6x0520.5x0514.8x058.9x0512.4x058.4
3.9x055.1x056.2x052.3x057.4x0517.5x053.8x050x057.9x052.6x0510.3x055.7x054.9x052x0514.5x052.5x053.6x053.1x057.3
6.6x058.9x055.8x058.6x053.6x0510.6x056.7x0510.4x050x058.4x052.8x0513.2x052.8x056.6x0520.2x0510.1x055.1x059.1x057
9.3x059.4x0511.7x057.6x0512.8x0522.4x059.4x055.5x0515.9x050x0511x055.3x055.5x051.7x0512.4x053.6x053.4x050.7x053.9
2.6x053.9x050.7x053.4x053.6x0512.4x051.7x055.5x055.3x0511x050x0515.9x055.5x059.4x0522.4x0512.8x057.6x0511.7x059.4
6.6x057x059.1x055.1x0510.1x0520.2x056.6x052.8x0513.2x052.8x058.4x050x0510.4x056.7x0510.6x053.6x058.6x055.8x058.9
1.1x057.3x053.1x053.6x052.5x0514.5x052x054.9x055.7x0510.3x052.6x057.5x050x053.8x0517.5x057.4x052.3x056.2x055.1
11.3x058.4x0512.4x058.9x0514.8x0520.5x0510.6x058.1x0517.1x056.3x0511.7x057.1x0512.4x050x0514.1x054.2x051.8x052.4x053.6
6.8x052.6x055.5x055.6x058.3x0510.9x055.5x057.6x058.7x0511.9x054.9x059.8x057.2x058.9x050x0513.6x0515.3x0513x0513.1
10x056.7x058x059.4x0510.2x056.9x058.8x0511.6x059x0516.1x057.4x0513.9x0510x0513.7x054.2x050x056x054.1x057.5
7.4x053.2x055.9x056.3x058.7x0510.2x056.1x058.3x058.9x0512.6x055.3x0510.6x057.8x0510.3x050.7x053.5x050x054x053.2
11.3x058.4x059.2x0511x0510.9x055.2x0510.1x0513.2x059.1x0517.8x058.6x0515.6x0511.1x0515.5x056x051.9x053.6x050x053.7
2.2x053.1x053.4x050.7x053.6x0514.9x051.2x052.9x057.8x058.3x052.8x055.7x053x059.4x055.2x058.9x056.1x0510.5x050
11.9x057.4x0511.8x059.5x0514.8x0517.2x0510.7x059.8x0516.1x0510.2x0511.2x0510x0512.8x054.6x057.6x0510.4x057.8x0512.2x059.7
ENDDATA
N = @SIZE( CITY);
MIN = @SUM( LINK:DIST * X);
@FOR( CITY( K):
@SUM( CITY( I)| I #NE# K:X( I,K)) = 1;
@SUM( CITY( J)| J #NE# K:X( K,J)) = 1;
@FOR( CITY( J)| J #GT# 1 #AND# J #NE# K:
U( J) >= U( K) + X ( K,J) -
( N - 2) * ( 1 - X( K,J)) +
( N - 3) * X( J,K));
);
@FOR( LINK:@BIN( X));
@FOR( CITY( K)| K #GT# 1:
U( K) = 1 + ( N - 2) * X( K,1)
);
END
这个是我们的BT老师让我们做的,20个点的tsp问题.前提是我们之前没有学过lingo,这个我是找的一个算是模板吧,输入20X20的数据后提示错误代码11.