57, 59, 67, 206

4 files changed, 120 insertions, 0 deletions

diff --git a/euler206.c b/euler206.c
new file mode 100644
index 0000000..2a5b007
--- /dev/null
+++ b/euler206.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+int test(long long t)
+{
+	t = t * t;
+	int b = 9;
+	while (b >= 1) {
+		if (t % 10 != b)
+			return 0;
+		b--;
+		t = t / 100;
+	}
+	return 1;
+}
+
+int main()
+{
+	/* test 1{0000000..5000000}{30,70} */
+	for (long long i = 10000000; i < 15000000; i++) {
+		long long t = i * 10 + 3;
+		if (test(t))
+			printf("%lld0\n", t);
+		t = i * 10 + 7;
+		if (test(t))
+			printf("%lld0\n", t);
+	}
+}
diff --git a/euler57.scm b/euler57.scm
new file mode 100644
index 0000000..aa8972a
--- /dev/null
+++ b/euler57.scm
@@ -0,0 +1,17 @@
+(define (expension n)
+ (define (e n)
+  (if (= n 1) (/ 1 2)
+   (/ 1 (+ 2 (e (- n 1))))))
+ (+ 1 (e n)))
+
+(define (digits n)
+ (if (< n 10) 1 (+ 1 (digits (quotient n 10)))))
+
+(define (solve n)
+ (if (= n 0) 0
+  (+ (solve (- n 1))
+   (let ((t (expension n)))
+	(if (> (digits (numerator t)) (digits (denominator t))) 1 0)))))
+
+(display (solve 1000))
+(newline)
diff --git a/euler59.py b/euler59.py
new file mode 100644
index 0000000..fe297c0
--- /dev/null
+++ b/euler59.py
@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+
+cipher_bytes = list(map(int, (input().split(','))))
+cipher_with_index = list(zip(range(0, len(cipher_bytes)), cipher_bytes))
+
+def decrypt(key, cwi):
+    def dec(tup):
+        i, c = tup
+        return c^key[i%3]
+
+    return list(map(dec, cwi))
+
+def toText(t):
+    s = ''
+    for c in t:
+        s = s + chr(c)
+    return s
+
+def asciisum(t):
+    s = 0
+    for c in t:
+        s = s + c
+    return s
+
+
+def allprint(a):
+    for c in a:
+        if c >= 0x7f or c < 0x20:
+            return False
+    return True
+
+
+key = [ord('a')] * 3
+
+for key[0] in range(ord('a'), ord('z')+1):
+    for key[1] in range(ord('a'), ord('z')+1):
+        for key[2] in range(ord('a'), ord('z')+1):
+            decrypted = decrypt(key, cipher_with_index)
+            if allprint(decrypted):
+                print(toText(decrypted))
+                print(asciisum(decrypted))
diff --git a/euler67.c b/euler67.c
new file mode 100644
index 0000000..f7a7291
--- /dev/null
+++ b/euler67.c
@@ -0,0 +1,35 @@
+#include <stdio.h>
+
+int max(int a, int b)
+{
+	if (a > b)
+		return a;
+	else
+		return b;
+}
+
+int main()
+{
+	int triangle[100][100];
+	int sol[100][100];
+	int i, j, n, a;
+
+	n = 0;
+	while (scanf("%d", &a)!=EOF) {
+		triangle[n][0] = a;
+		for (i = 1; i <= n; i++)
+			scanf("%d", &triangle[n][i]);
+		n++;
+	}
+
+	for (i = 0; i < n; i++)
+		sol[n-1][i] = triangle[n-1][i];
+
+	for (i = n-2; i >= 0; i--) {
+		for (j = 0; j <= i; j++) {
+			sol[i][j] = triangle[i][j] + max(sol[i+1][j], sol[i+1][j+1]);
+		}
+	}
+
+	printf("%d\n", sol[0][0]);
+}