/* ===== 进阶数组与切片 =====
 * test19_hardarray — 多维数组、多维切片、切片构造、字符串测试
 * 难度：4/5
 * 验证点：多维数组索引与修改、多维切片、切片字段读写、扁平指针访问、字符串切片
 */
fn test_string() i32 {
    /* ============================
     * String test: str is []u8
     * ============================ */
    var data: *u8 = "hello";
    var s: []u8 = { .ptr = data, .len = 5 };

    if s.len != 5 { ret 100; }
    if s[0] != 104 { ret 101; } /* 'h' */
    if s[1] != 101 { ret 102; } /* 'e' */
    if s[4] != 111 { ret 103; } /* 'o' */

    /* Slice the string slice */
    var sub: []u8 = s[1..4];
    if sub.len != 3 { ret 104; }
    if sub[0] != 101 { ret 105; } /* 'e' */
    if sub[2] != 108 { ret 106; } /* 'l' */

    /* Modify through slice → original changes */
    s[0] = 72; /* 'H' */
    if data[0] != 72 { ret 107; }

    /* Full slice */
    var full: []u8 = s[0..];
    if full.len != 5 { ret 108; }
    if full[0] != 72 { ret 109; }

    /* Construct slice from pointer via field assignment */
    var s2: []u8;
    s2.ptr = data;
    s2.len = 3;
    if s2.len != 3 { ret 110; }
    if s2[0] != 72 { ret 111; }

    ret 0;
}

fn main() i32 {
    /* ============================
     * Part 1: 多维数组（逐元素初始化）
     * ============================ */
    var matrix: [2][3]i32;
    matrix[0][0] = 1;  matrix[0][1] = 2;  matrix[0][2] = 3;
    matrix[1][0] = 4;  matrix[1][1] = 5;  matrix[1][2] = 6;

    if matrix[0][0] != 1 { ret 1; }
    if matrix[0][1] != 2 { ret 2; }
    if matrix[0][2] != 3 { ret 3; }
    if matrix[1][0] != 4 { ret 4; }
    if matrix[1][1] != 5 { ret 5; }
    if matrix[1][2] != 6 { ret 6; }

    /* 元素修改 */
    matrix[0][0] = 10;
    matrix[1][2] = 60;
    if matrix[0][0] != 10 { ret 7; }
    if matrix[1][2] != 60 { ret 8; }

    /* ============================
     * Part 2: 嵌套循环遍历多维数组
     * ============================ */
    var big: [3][4]i32;
    big[0][0] = 1;  big[0][1] = 2;  big[0][2] = 3;  big[0][3] = 4;
    big[1][0] = 5;  big[1][1] = 6;  big[1][2] = 7;  big[1][3] = 8;
    big[2][0] = 9;  big[2][1] = 10; big[2][2] = 11; big[2][3] = 12;

    var total: i32 = 0;
    var i: i32 = 0;
    while i < 3 {
        var j: i32 = 0;
        while j < 4 {
            total = total + big[i][j];
            j = j + 1;
        }
        i = i + 1;
    }
    if total != 78 { ret 9; }

    /* ============================
     * Part 3: &取地址 + 扁平指针访问
     * ============================ */
    var flat: *i32 = &matrix[0][0];
    if flat[0] != 10 { ret 10; }
    if flat[1] != 2  { ret 11; }
    if flat[2] != 3  { ret 12; }
    if flat[3] != 4  { ret 13; }
    if flat[4] != 5  { ret 14; }
    if flat[5] != 60 { ret 15; }

    /* ============================
     * Part 4: 多维数组切片
     * ============================ */
    var row: []i32 = matrix[0][0..3];
    if row.len != 3 { ret 16; }
    if row[0] != 10 { ret 17; }
    if row[1] != 2  { ret 18; }
    if row[2] != 3  { ret 19; }

    /* 切取第二行 */
    var row2: []i32 = matrix[1][0..];
    if row2.len != 3 { ret 20; }
    if row2[0] != 4  { ret 21; }
    if row2[2] != 60 { ret 22; }

    /* ============================
     * Part 5: 切片的切片
     * ============================ */
    var sub: []i32 = row[1..3];
    if sub.len != 2 { ret 23; }
    if sub[0] != 2  { ret 24; }
    if sub[1] != 3  { ret 25; }

    /* ============================
     * Part 6: 切片字段读写
     * ============================ */
    var arr: [4]i32;
    arr[0] = 100; arr[1] = 200; arr[2] = 300; arr[3] = 400;
    var custom: []i32;
    custom.ptr = &arr[1];
    custom.len = 2;

    if custom.len != 2 { ret 26; }
    if custom[0] != 200 { ret 27; }
    if custom[1] != 300 { ret 28; }

    /* 修改切片长度 */
    custom.len = 3;
    if custom.len != 3 { ret 29; }
    if custom[2] != 400 { ret 30; }

    /* ============================
     * Part 7: 空范围 / 全切片
     * ============================ */
    var full: []i32 = arr[0..];
    if full.len != 4 { ret 31; }
    if full[0] != 100 { ret 32; }
    if full[3] != 400 { ret 33; }

    /* ============================
     * Part 8: 从指针构造切片
     * ============================ */
    var data: [5]i32;
    data[0] = 10; data[1] = 20; data[2] = 30; data[3] = 40; data[4] = 50;
    var p: *i32 = &data[2];
    var from_ptr: []i32 = { .ptr = p, .len = 2 };
    var from_ptr2: []i32;
    from_ptr2.ptr = p;
    from_ptr2.len = 2;

    if from_ptr.len != 2 { ret 34; }
    if from_ptr[0] != 30 { ret 35; }
    if from_ptr[1] != 40 { ret 36; }

    if from_ptr2.len != 2 { ret 37; }
    if from_ptr2[0] != 30 { ret 38; }
    if from_ptr2[1] != 40 { ret 39; }

    /* ============================
     * Part 9: 切片元素修改反映到原始数组
     * ============================ */
    row2[0] = 99;
    if matrix[1][0] != 99 { ret 40; }

    /* ============================
     * Part 10: 1D 数组字面量仍然正常
     * ============================ */
    var literal: [3]i32 = [3]i32{10, 20, 30};
    if literal[0] != 10 { ret 41; }
    if literal[1] != 20 { ret 42; }
    if literal[2] != 30 { ret 43; }

    /* ============================
     * Part 11: 字符串切片测试
     * ============================ */
    var r: i32 = test_string();
    if r != 0 { ret r; }

    ret 0;
}