You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
83 lines
1.4 KiB
83 lines
1.4 KiB
11 months ago
|
int array[110];
|
||
|
|
int n;
|
||
|
|
void init(int n) {
|
||
|
|
int i = 1;
|
||
|
|
while (i <= n * n + 1) {
|
||
|
|
array[i] = -1;
|
||
|
|
i = i + 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int findfa(int a) {
|
||
|
|
if (array[a] == a)
|
||
|
|
return a;
|
||
|
|
else {
|
||
|
|
array[a] = findfa(array[a]);
|
||
|
|
return array[a];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
void mmerge(int a, int b) {
|
||
|
|
int m = findfa(a);
|
||
|
|
int n = findfa(b);
|
||
|
|
if (m != n) array[m] = n;
|
||
|
|
}
|
||
|
|
int main() {
|
||
|
|
int t, m;
|
||
|
|
int a, b;
|
||
|
|
t = 1;
|
||
|
|
while (t) {
|
||
|
|
t = t - 1;
|
||
|
|
n = 4;
|
||
|
|
m = 10;
|
||
|
|
int i = 0;
|
||
|
|
int flag = 0;
|
||
|
|
init(n);
|
||
|
|
int k = n * n + 1;
|
||
|
|
|
||
|
|
while (i < m) {
|
||
|
|
a = getint();
|
||
|
|
b = getint();
|
||
|
|
|
||
|
|
if (!flag) {
|
||
|
|
int loc = n * (a - 1) + b;
|
||
|
|
|
||
|
|
array[loc] = loc;
|
||
|
|
if (a == 1) {
|
||
|
|
array[0] = 0;
|
||
|
|
mmerge(loc, 0);
|
||
|
|
}
|
||
|
|
if (a == n) {
|
||
|
|
array[k] = k;
|
||
|
|
mmerge(loc, k);
|
||
|
|
}
|
||
|
|
if (b < n && array[loc + 1] != -1) {
|
||
|
|
mmerge(loc, loc + 1);
|
||
|
|
}
|
||
|
|
if (b > 1 && array[loc - 1] != -1) {
|
||
|
|
mmerge(loc, loc - 1);
|
||
|
|
}
|
||
|
|
if (a < n && array[loc + n] != -1) {
|
||
|
|
mmerge(loc, loc + n);
|
||
|
|
}
|
||
|
|
if (a > 1 && array[loc - n] != -1) {
|
||
|
|
mmerge(loc, loc - n);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (array[0] != -1 && array[k] != -1 && findfa(0) == findfa(k)) {
|
||
|
|
flag = 1;
|
||
|
|
int tmp = i + 1;
|
||
|
|
putint(tmp);
|
||
|
|
putch(10);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
i = i + 1;
|
||
|
|
}
|
||
|
|
if (!flag) {
|
||
|
|
putint(-1);
|
||
|
|
putch(10);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|