题目描述

<o:wrapblock> <v:group id="_x0000_s1026" o:allowincell="f" coordsize="4500,4836" style="margin-top: 67.85pt; z-index: 1; left: 0px; margin-left: 87.85pt; width: 3in; position: absolute; height: 231.1pt; text-align: left"> <v:shapetype id="_x0000_t202" coordsize="21600,21600" path="m,l,21600r21600,l21600,xe" o:spt="202"> <v:stroke joinstyle="miter"></v:stroke> <v:path o:connecttype="rect" gradientshapeok="t"></v:path> </v:shapetype> <v:shape id="_x0000_s1052" stroked="f" type="#_x0000_t202" style="left: 1980px; width: 900px; position: absolute; top: 4368px; height: 468px; mso-wrap-style: square"> <v:textbox> </v:textbox> </v:shape> </v:group> </o:wrapblock>

图一 <o:p></o:p>

<w:wrap type="topAndBottom"></w:wrap>
有一个n*n的网格，每一“格”上有一个可以翻转的方块，方块的两面分别涂成黑、白两种颜色。另外，有一个沿着网格线活动的东西——不妨称之为“动子”。初始时，每个方块随机地被翻成黑或白色，“动子”停在网格线的某个顶点上。例如如图一就是一个4*4的网格的一种可能的开局情况。

“动子”在网格线上运动时，从一个顶点A到相邻的另一个顶点B之后，以网格线AB为边的两个或一个网格上的方块就会翻转——白变黑，黑变白。例如图一的“动子”向右移动一步之后变成图二，向下移动一步之后变成图三。

<o:p> </o:p>

<v:group id="_x0000_s1052" o:allowincell="f" coordsize="4500,4836" style="margin-top: 298.5pt; z-index: 2; left: 0px; margin-left: 208.4pt; width: 213.05pt; position: absolute; height: 228.15pt; text-align: left"> <v:rect id="_x0000_s1053" strokeweight="1.25pt" strokecolor="blue" fillcolor="#9cf" style="left: 180px; width: 4320px; position: absolute; height: 4320px; mso-wrap-style: square"></v:rect> <v:line id="_x0000_s1054" strokeweight="1pt" strokecolor="#36f" to="2340,4368" from="2340,0" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1055" strokeweight="1pt" strokecolor="#36f" to="1260,4368" from="1260,0" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1056" strokeweight="1pt" strokecolor="#36f" to="3420,4368" from="3420,0" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1057" strokeweight="1pt" strokecolor="#36f" to="4500,2184" from="180,2184" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1058" strokeweight="1pt" strokecolor="#36f" to="4500,1092" from="180,1092" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1059" strokeweight="1pt" strokecolor="#36f" to="4500,3276" from="180,3276" style="position: absolute; mso-wrap-style: square"></v:line> <v:oval id="_x0000_s1060" strokecolor="lime" fillcolor="#f90" style="width: 360px; position: absolute; top: 3072px; height: 360px; mso-wrap-style: square"></v:oval> <v:rect id="_x0000_s1061" style="left: 360px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1062" style="left: 1440px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1063" style="left: 2520px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1064" fillcolor="black" style="left: 3600px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1065" style="left: 3600px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1066" fillcolor="black" style="left: 2520px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1067" style="left: 1440px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1068" fillcolor="black" style="left: 360px; width: 720px; position: absolute; top: 2400px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1069" fillcolor="black" style="left: 360px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1070" fillcolor="black" style="left: 1440px; width: 720px; position: absolute; top: 2340px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1071" style="left: 2520px; width: 720px; position: absolute; top: 2340px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1072" style="left: 3600px; width: 720px; position: absolute; top: 2340px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1073" style="left: 3600px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1074" fillcolor="black" style="left: 2520px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1075" style="left: 1440px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1076" style="left: 360px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:shapetype id="_x0000_t202" coordsize="21600,21600" path="m,l,21600r21600,l21600,xe" o:spt="202"> <v:stroke joinstyle="miter"></v:stroke> <v:path o:connecttype="rect" gradientshapeok="t"></v:path> </v:shapetype> <v:shape id="_x0000_s1077" stroked="f" type="#_x0000_t202" style="left: 1980px; width: 900px; position: absolute; top: 4368px; height: 468px; mso-wrap-style: square"> <v:textbox> </v:textbox> </v:shape> </v:group>

图三 <o:p></o:p>

<o:wrapblock> <v:group id="_x0000_s1026" o:allowincell="f" coordsize="4320,4836" style="margin-top: 299.2pt; z-index: 1; left: 0px; margin-left: -11.1pt; width: 207.8pt; position: absolute; height: 228.15pt; text-align: left"> <v:rect id="_x0000_s1027" strokeweight="1.25pt" strokecolor="blue" fillcolor="#9cf" style="width: 4320px; position: absolute; height: 4320px; mso-wrap-style: square"></v:rect> <v:line id="_x0000_s1028" strokeweight="1pt" strokecolor="#36f" to="2160,4368" from="2160,0" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1029" strokeweight="1pt" strokecolor="#36f" to="1080,4368" from="1080,0" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1030" strokeweight="1pt" strokecolor="#36f" to="3240,4368" from="3240,0" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1031" strokeweight="1pt" strokecolor="#36f" to="4320,2184" from="0,2184" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1032" strokeweight="1pt" strokecolor="#36f" to="4320,1092" from="0,1092" style="position: absolute; mso-wrap-style: square"></v:line> <v:line id="_x0000_s1033" strokeweight="1pt" strokecolor="#36f" to="4320,3276" from="0,3276" style="position: absolute; mso-wrap-style: square"></v:line> <v:oval id="_x0000_s1034" strokecolor="lime" fillcolor="#f90" style="left: 900px; width: 360px; position: absolute; top: 2028px; height: 360px; mso-wrap-style: square"></v:oval> <v:rect id="_x0000_s1035" style="left: 180px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1036" style="left: 1260px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1037" style="left: 2340px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1038" fillcolor="black" style="left: 3420px; width: 720px; position: absolute; top: 156px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1039" style="left: 3420px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1040" fillcolor="black" style="left: 2340px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1041" style="left: 1260px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1042" fillcolor="black" style="left: 180px; width: 720px; position: absolute; top: 2400px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1043" style="left: 180px; width: 720px; position: absolute; top: 1248px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1044" fillcolor="black" style="left: 1260px; width: 720px; position: absolute; top: 2340px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1045" style="left: 2340px; width: 720px; position: absolute; top: 2340px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1046" style="left: 3420px; width: 720px; position: absolute; top: 2340px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1047" style="left: 3420px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1048" fillcolor="black" style="left: 2340px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1049" style="left: 1260px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:rect id="_x0000_s1050" style="left: 180px; width: 720px; position: absolute; top: 3432px; height: 720px; mso-wrap-style: square"></v:rect> <v:shape id="_x0000_s1051" stroked="f" type="#_x0000_t202" style="left: 1800px; width: 900px; position: absolute; top: 4368px; height: 468px; mso-wrap-style: square"> <v:textbox>

图二 <o:p></o:p>

</v:textbox> </v:shape> <w:wrap type="topAndBottom"></w:wrap> </v:group> </o:wrapblock>

<o:p></o:p>

给定一个初始状态，求“动子”的一种运动轨迹，可以将所有的格子变成白色，最后“动子”停在哪里是无所谓的。

输入格式

第一行T表示数据组数 <o:p></o:p>

对于每组数据，第一行n表示网格大小 <o:p></o:p>

接下来n行n列描述初始网格，0表示白色，1表示黑色 <o:p></o:p>

接下来一行x y表示动子的初始位置，左上角为(1,1)，左下角为(n+1,1) <o:p></o:p>

输出格式

   对于每组数据，在一行中输出一个相应的答案 <o:p></o:p>

    若无解则输出“No Solution!”，否则输出一个仅包含‘L’‘R’‘U’‘D’（上下左右）的字符串表示“动子”的移动路线，有多解时任意输出任意一组解即可，要求输出的解长度不超过5000 <o:p></o:p>

<o:p></o:p>

3
1
1
1 1
2
0 1
1 0
2 2
7
1 1 0 0 1 0 1
1 1 0 1 0 1 1
1 0 1 0 1 1 1
0 1 0 1 1 0 1
1 1 1 1 1 1 1
1 1 1 1 1 1 1
1 1 1 1 1 1 1
1 1

R
ULDR
No Solution!

数据范围与约定

T≤5，1≤n≤15

请不要提交，期待SPJ