2043. 简易银行系统

src/arr.rs

@@ -13,13 +13,63 @@ pub fn make_arr(s: &str) -> Vec<i32> {
 }
 
 pub fn make_matrix(s: &str) -> Vec<Vec<i32>> {
-    s.trim_matches(&['[', ']'][..])
-        .split("],[")
-        .map(|row| {
-            row.trim_matches(&['[', ']'][..])
-                .split(',')
-                .map(|x| x.trim().parse::<i32>().unwrap())
-                .collect()
-        })
-        .collect()
+    let s = s.trim();
+
+    // Remove only the outermost pair of brackets if present, e.g. "[[1,2],[3,4]]" -> "[1,2],[3,4]"
+    let inner = if s.len() >= 2 && s.starts_with('[') && s.ends_with(']') {
+        &s[1..s.len() - 1]
+    } else {
+        s
+    }
+    .trim();
+
+    if inner.is_empty() {
+        return Vec::new();
+    }
+
+    let bytes = inner.as_bytes();
+    let mut i = 0usize;
+    let mut rows: Vec<Vec<i32>> = Vec::new();
+    while i < bytes.len() {
+        // find next '['
+        while i < bytes.len() && bytes[i] != b'[' {
+            i += 1;
+        }
+        if i >= bytes.len() {
+            break;
+        }
+        let start = i + 1; // byte index after '['
+        i = start;
+        // find matching ']'
+        while i < bytes.len() && bytes[i] != b']' {
+            i += 1;
+        }
+        let end = i; // exclusive
+        // move i past ']' for next iteration (if in bounds)
+        if i < bytes.len() {
+            i += 1;
+        }
+
+        if end <= start {
+            // empty row like []
+            rows.push(Vec::new());
+            continue;
+        }
+
+        let row_str = &inner[start..end];
+        let row_vec: Vec<i32> = row_str
+            .split(',')
+            .map(|x| {
+                let x = x.trim();
+                if x == "null" || x.is_empty() {
+                    -1
+                } else {
+                    x.parse::<i32>().unwrap()
+                }
+            })
+            .collect();
+        rows.push(row_vec);
+    }
+
+    rows
 }