Add kattis prob wheresmyinternet in C

kattis/wheresmyinternet/solution.c

@@ -0,0 +1,46 @@
+#include <stdio.h>
+
+long int parent[200005];
+
+long int find(long int a) {
+    while (a != parent[a]) {
+        a = parent[a];
+    }
+    return a;
+}
+
+void merge(long int a, long int b) {
+    a = find(a);
+    b = find(b);
+    if (a < b) {
+        parent[b] = a;
+    } else {
+        parent[a] = b;
+    }
+}
+
+int main() {
+    long int numhouse, numlink;
+    scanf("%ld %ld", &numhouse, &numlink);
+    long int i;
+    for (i = 1; i <= numhouse; ++i) {
+        parent[i] = i;
+    }
+    for (i = 0; i < numlink; ++i) {
+        long int a, b;
+        scanf("%ld %ld", &a, &b);
+        merge(a, b);
+    }
+    long int connected = find(1);
+    short allConnected = 1;
+    for (i = 2; i <= numhouse; ++i) {
+        if (find(i) != connected) {
+            allConnected = 0;
+            printf("%ld\n", i);
+        }
+    }
+    if (allConnected > 0) {
+        printf("Connected\n");
+    }
+    return 0;
+}