fix: invalid c solution for lc problem: No.0709

No.0709.To Lower Case

Author: YangFong

solution/0700-0799/0709.To Lower Case/Solution.c

@@ -1,11 +1,9 @@
-impl Solution {
-    pub fn to_lower_case(s: String) -> String {
-        String::from_utf8(
-            s.as_bytes()
-                .iter()
-                .map(|&c| c + if c >= b'A' && c <= b'Z' { 32 } else { 0 })
-                .collect(),
-        )
-        .unwrap()
+char *toLowerCase(char *s) {
+    int n = strlen(s);
+    for (int i = 0; i < n; i++) {
+        if (s[i] >= 'A' && s[i] <= 'Z') {
+            s[i] |= 32;
+        }
     }
+    return s;
 }