/* ===== 模块3：控制流 =====
 * test05_control — 分支与循环
 * 难度：2/5
 * 验证点：if/else、while、loop、break、continue
 */
fn main() i32 {
    /* ---- if/else ---- */
    var x: i32 = 10;
    if x > 5 {
        x = 0;
    } else {
        x = 1;
    }
    if x != 0 { ret 1; }

    /* else 分支 */
    var y: i32 = 1;
    if y > 5 {
        y = 10;
    } else {
        y = 20;
    }
    if y != 20 { ret 2; }

    /* if 不带 else */
    var z: i32 = 0;
    if z == 0 {
        z = 99;
    }
    if z != 99 { ret 3; }

    /* ---- while ---- */
    var i: i32 = 0;
    while i < 5 {
        i = i + 1;
    }
    if i != 5 { ret 4; }

    /* while 条件为 false */
    var j: i32 = 0;
    while j > 0 {
        j = j + 1;
    }
    if j != 0 { ret 5; }

    /* ---- loop / break ---- */
    var k: i32 = 0;
    loop {
        k = k + 1;
        if k >= 3 { break; }
    }
    if k != 3 { ret 6; }

    /* ---- continue ---- */
    var n: i32 = 0;
    var m: i32 = 0;
    while n < 5 {
        n = n + 1;
        if n == 3 { continue; }
        m = m + 1;
    }
    if n != 5 { ret 7; }
    if m != 4 { ret 8; }

    /* ---- 嵌套控制流 ---- */
    var total: i32 = 0;
    var p: i32 = 0;
    while p < 3 {
        var q: i32 = 0;
        while q < 4 {
            total = total + 1;
            q = q + 1;
        }
        p = p + 1;
    }
    if total != 12 { ret 9; }

    ret 0;
}