I’ve came across on an interview with this problem: https://www.chegg.com/homework-help/questions-and-answers/board-2-rows-n-columns-represented-matrix-m-rows-numbered-0-1-top-bottom-columns-numbered--q38897583

I developed a solution:

```
public static boolean esPosible(int U, int L, int[] c) {
for (int i = 0; i < c.length; i++) {
if (c[i] == 2) {
L--;
U--;
}
}
if (U < 0 || L < 0) {
return false;
}
for (int i = 0; i < c.length; i++) {
if (c[i] == 1) {
if (U> 0) {
U--;
} else {
L--;
}
}
}
return U == 0 && L == 0;
}
public String solution(int U, int L, int[] c) {
boolean posible = esPosible(U, L, c);
String res = "IMPOSSIBLE";
if (posible) {
String res1 = "", res2 = "";
for (int i = 0; i < c.length; i++) {
if (c[i] == 0) {
res1 += "0";
res2 += "0";
}
if (c[i] == 2) {
U--; L--;
res1 += "1";
res2 += "1";
}
if (c[i] == 1) {
if (U > 0) {
U--;
res1+="1";
res2+="0";
} else {
L--;
res1+="0";
res2+="1";
}
}
}
res = res1 + "," + res2;
}
return res;
}
```

But I got 70% of success cases.

Is something wrong? I really dont know what is wrong, it seems pretty greedy for me

Many thanks