update

poj/2799.ip-networks/main.cc

@@ -0,0 +1,66 @@
+#include <cstdio>
+#include <cstdlib>
+
+const int M = 1000;
+
+char buf[16];
+
+int mask[] = {1 << 7, 1 << 6, 1 << 5, 1 << 4, 1 << 3, 1 << 2, 1 << 1, 1};
+
+void itob(int i, bool *b) {
+    for (int j = 0; j < 8; j++) {
+        b[j] = i & mask[j];
+    }
+}
+
+int btoi(bool *b) {
+    int i = 0;
+    for (int j = 0; j < 8; j++) {
+        if (b[j]) i += mask[j];
+    }
+    return i;
+}
+
+bool ip[M][32];
+
+void print_ip(int m) {
+    for (int i = 0; i < m; i++) {
+        for (int j = 0; j < 32; j++) {
+            printf("%d", ip[i][j]);
+        }
+        printf("\n");
+    }
+}
+
+int main() {
+    int m;
+    scanf("%d\n", &m);
+    for (int i = 0; i < m; i++) {
+        scanf("%s\n", buf);
+        for (int pre = 0, cur = 0, j = 0; j < 4; j++) {
+            while (buf[cur] != '.' && buf[cur] != 0) cur++;
+            buf[cur] = 0;
+            int num = atoi(buf + pre);
+            itob(num, ip[i] + 8 * j);
+            cur++;
+            pre = cur;
+        }
+    }
+    int i;
+    for (i = 0; i < 32; i++) {
+        bool flag = ip[0][i];
+        for (int j = 0; j < m; j++) {
+            if (ip[j][i] != flag) goto end;
+        }
+    }
+end:
+    for (int j = i; j < 32; j++) {
+        ip[0][j] = false;
+    }
+    printf("%d.%d.%d.%d\n", btoi(ip[0]), btoi(ip[0] + 8), btoi(ip[0] + 16), btoi(ip[0] + 24));
+    for (int j = 0; j < i; j++) {
+        ip[0][j] = true;
+    }
+    printf("%d.%d.%d.%d\n", btoi(ip[0]), btoi(ip[0] + 8), btoi(ip[0] + 16), btoi(ip[0] + 24));
+    return 0;
+}