TheAlgorithms · yashasvi-goel · Oct 5, 2020 · Oct 9, 2020
diff --git a/project_euler/problem_59/sol1.c b/project_euler/problem_59/sol1.c
@@ -0,0 +1,96 @@
+/**
+ * \file
+ * \brief [Problem 59](https://projecteuler.net/problem=59) solution -
+ * optimization using look-up array
+ * \author [Yashasvi Goel](https://github.com/yashasvi-goel/)
+ *
+ */
+#include<stdio.h>
+int check(int a)
+{
+    if(a>=65&&a<=90)
+        return 1;
+    else if(a>=97&&a<=122)
+        return 1;
+    else if(a>=48&&a<=59)
+        return 1;
+    else if(a=='('||a==')'||a=='.'||a==','||a=='\''||a=='?'||a=='-'||a=='!'||a==' ')
+        return 1;
+    return 0;
+}
+int main()
+{
+    int n;
+    scanf("%d",&n);
+    int *a=(int*)malloc(sizeof(int)*n);
+    for(int i=0;i<n;i++)
+        scanf("%d",&a[i]);
+    int x=0;
+    int h=0;
+    for(int i=97;i<123;i++)
+    {
+        x=0;
+        h=0;
+        for(int j=0;j<n;j=j+3)
+        {
+            x=i^a[j];
+            if(!check(x))
+            {
+                h=1;
+                break;
+            }
+        }
+        if(h==0)
+        {
+            printf("%c",i);
+            break;
+        }
+    }
+    for(int i='a';i<='z';i++)
+    {
+        x=0;
+        h=0;
+        for(int j=1;j<n;j=j+3)
+        {                
+            x=i^a[j];
+            if(!check(x))
+            {
+                h=1;
+        //        printf(":%c:%c\n",x,i);
+                break;
+            }
+        }
+        if(h==0)
+        {
+            printf("%c",i);
+            break;
+        }
+    }
+    for(int i=97;i<123;i++)
+    {
+        x=0;
+        h=0;
+        for(int j=2;j<n;j=j+3)
+        {                
+            x=i^a[j];
+            if(!check(x))
+            {
+                h=1;
+                break;
+            }
+        }
+        if(h==0)
+        {
+            printf("%c",i);
+            break;
+        }
+    }
+    return 0;
+}
+/*
+Input
+82
+32 66 50 20 11 0 42 66 33 19 13 20 47 66 37 14 58 67 43 23 14 17 49 67 46 20 6 51 66 55 9 39 67 45 3 25 56 66 39 14 37 34 65 51 22 8 1 40 65 32 17 14 21 45 65 36 12 57 66 41 20 15 19 50 66 44 23 7 49 65 54 11 36 66 47 0 24 58 65 38 12 38
+Output
+abc
+*/