fixed up 4, finished 8, 9, 10, started 11

1 files changed, 154 insertions, 12 deletions

diff --git a/src/main.zig b/src/main.zig
index 8966363..56c15fe 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -77,7 +77,7 @@ fn p3() void {
     std.debug.warn("{}\n", .{biggest});
 }
 
-fn p4() !void {
+fn p4() void {
     var i: usize = 0;
     var j: usize = 0;
     var str: [6]u8 = undefined;
@@ -85,13 +85,16 @@ fn p4() !void {
     while (i < 1000) : (i += 1) {
         j = 0;
         while (j < 1000) : (j += 1) {
-            _ = try std.fmt.bufPrint(&str, "{}", .{i * j});
-            if (i * j > largest and
-                str[0] == str[5] and
-                str[1] == str[4] and
-                str[2] == str[3])
-            {
-                largest = i * j;
+            if (std.fmt.bufPrint(&str, "{}", .{i * j})) |val| {
+                if (i * j > largest and
+                    str[0] == str[5] and
+                    str[1] == str[4] and
+                    str[2] == str[3])
+                {
+                    largest = i * j;
+                }
+            } else |err| {
+                print("{}\n", .{err});
             }
         }
     }
@@ -111,6 +114,7 @@ fn p5() void {
         while (j != 0) : (j -= 1) {
             if (i % j != 0) {
                 found = true;
+                break;
             }
         }
 
@@ -146,17 +150,155 @@ fn p7() void {
     print("{}\n", .{i - 1});
 }
 
+fn remove(str: []u8, c: u8) void {
+    var tmp: [1024]u8 = undefined;
+    var counter: u16 = 0;
+    for (str) |char| {
+        if (char != c) {
+            tmp[counter] = char;
+            counter += 1;
+        }
+    }
+
+    insert(str, &tmp);
+}
+
+fn insert(output: []u8, input: []const u8) void {
+    for (input) |_, i| {
+        output[i] = input[i];
+    }
+}
+
+fn len(str: []u8) usize {
+    var i: usize = 0;
+    for (str) |c| {
+        if (c < 128) {
+            i += 1;
+        } else {
+            break;
+        }
+    }
+
+    return i;
+}
+
 fn p8() void {
-    print("{}\n", .{1});
+    var largest: usize = 0;
+    if (std.fs.cwd().openFile("p8", .{ .read = true })) |file| {
+        var str: [1024]u8 = undefined;
+        if (file.read(&str)) |val| {
+            remove(&str, '\n');
+            var i: usize = 0;
+            while (i < len(&str) - 12) : (i += 1) {
+                var product: usize = 1;
+                for (str[i .. i + 13]) |c| {
+                    var n: usize = c - 48;
+                    if (n < 10) {
+                        product *= c - 48;
+                    } else {
+                        break;
+                    }
+                }
+                if (product > largest) {
+                    largest = product;
+                }
+            }
+        } else |err| {
+            print("{}\n", .{err});
+        }
+    } else |err| {
+        print("{}\n", .{err});
+    }
+    print("{}\n", .{largest});
+}
+
+fn sqrt(x: f64) f64 {
+    var z: f64 = 1;
+    var i: u8 = 1;
+    while (i <= 10) : (i += 1) {
+        z -= (z * z - x) / (2 * z);
+    }
+    return z;
+}
+
+fn p9() void {
+    var c: usize = 1;
+    main: while (c <= 1000) : (c += 1) {
+        //var c2: usize = c*c;
+        //while (b
+        var b: usize = 1;
+        while (b < c) : (b += 1) {
+            var a: usize = 1;
+            while (a < b) : (a += 1) {
+                if (a * a + b * b == c * c and a + b + c == 1000) {
+                    print("{}\n", .{a * b * c});
+                    break :main;
+                }
+            }
+        }
+    }
+}
+
+//fn sum(array: []usize) usize {
+//    var counter: usize = 0;
+//    for (array) |i| {
+//        counter += i;
+//    }
+//    return counter;
+//}
+
+fn p10() void {
+    const size: usize = 2_000_001;
+    var primes: [size]bool = undefined;
+    for (primes) |prime, i| {
+        primes[i] = true;
+    }
+
+    var i: usize = 2;
+    while (i < size) : (i += 1) {
+        if (primes[i]) {
+            var j: usize = 2;
+            while (j * i < size) : (j += 1) {
+                primes[j * i] = false;
+            }
+        }
+    }
+
+    var sum: usize = 0;
+
+    for (primes) |prime, num| {
+        if (prime and num != 1) {
+            sum += num;
+        }
+    }
+    print("{}\n", .{sum});
+}
+
+fn p11() void {
+    var array: [20][20]usize = undefined;
+
+    if (std.fs.cwd().openFile("p11", .{ .read = true })) |file| {
+        var str: [4096]u8 = undefined;
+        if (file.read(&str)) |val| {
+            print("{}", .{str[0]});
+        } else |err| {
+            print("{}\n", .{err});
+        }
+    } else |err| {
+        print("{}\n", .{err});
+    }
 }
 
 pub fn main() !void {
     //p1();
     //p2();
     //p3();
-    //_ = try p4();
+    //p4();
     //p5();
     //p6();
-    p7();
-    //p8();
+    //p7();
+    p8();
+    p9();
+    //p10();
+    //p11();
 }