aboutsummaryrefslogtreecommitdiff
path: root/convert_num_hex.c
diff options
context:
space:
mode:
authorJack Sangdahl <[email protected]>2025-03-15 02:05:58 -0600
committerJack Sangdahl <[email protected]>2025-03-15 02:05:58 -0600
commit5e923e65f2bef08dd917ca1cf9581a7a60bab8c9 (patch)
tree8b7f0c5080c8c093839c1e9b35d808287e8e7f17 /convert_num_hex.c
parent95c460fc44a3ccee0b366b67cf47df0576f2fa32 (diff)
downloadleetcode-5e923e65f2bef08dd917ca1cf9581a7a60bab8c9.tar.gz
leetcode-5e923e65f2bef08dd917ca1cf9581a7a60bab8c9.zip
405. convert a number to hexadecimal
Diffstat (limited to 'convert_num_hex.c')
-rw-r--r--convert_num_hex.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/convert_num_hex.c b/convert_num_hex.c
new file mode 100644
index 0000000..421706b
--- /dev/null
+++ b/convert_num_hex.c
@@ -0,0 +1,35 @@
+// 405. Convert a Number to Hexadecimal
+#include "leetcode.h"
+
+/*
+ * given a 32 bit integer 'num', return a string representing its hexadecimal
+ * representation. for negative integers, two's complement method is used. all
+ * the letters in the answer string should be lowercase characters, nd there not
+ * be any leading zeros in the answer except for the zero itself. note: you are
+ * not allowed to use any built-in library method to directly solve this
+ * problem.
+ */
+
+char *toHex(int num) {
+ char *ans = (char *)malloc(sizeof(char) * 10), step;
+ uint x = num, i = 0;
+ ans[9] = '\0';
+ while (1) {
+ step = x & 0xF;
+ ans[8 - i] = step > 9 ? 'a' + step - 10 : '0' + step;
+ x >>= 4;
+ if (!x)
+ break;
+ i++;
+ }
+ return &ans[8 - i];
+}
+
+int main() {
+ char *th1 = toHex(26);
+ char *th2 = toHex(-1);
+ printf("%s\n", th1); // expect: 1a
+ printf("%s\n", th2); // expect: ffffffff
+ free(th1);
+ free(th2);
+}