add solution of Eldorado

Author: husinassegaff

20. Dynamic Programming/Eldorado.cpp

@@ -0,0 +1,44 @@
+// Link problem : https://www.spoj.com/problems/ELDORADO/
+
+#include <stdio.h>
+#include <algorithm>
+
+int main()
+{
+    int numbers, chainlen;
+    int number[128];
+    long long ways[2][128];
+    int i, j, k;
+    long long totways;
+
+    while ((scanf("%d%d", &numbers, &chainlen) == 2) && numbers)
+    {
+        for (i = 0; i < numbers; i++)
+            scanf("%d", &number[i]);
+        for (i = 0; i < numbers; i++)
+            ways[1][i] = 1;
+
+        for (j = 2; j <= chainlen; j++)
+        {
+            for (i = 0; i < numbers; i++)
+            {
+                ways[j % 2][i] = 0;
+
+                for (k = 0; k < i; k++)
+                {
+                    if (number[k] < number[i])
+                    {
+                        ways[j % 2][i] += ways[((j % 2) + 1) % 2][k];
+                    }
+                }
+            }
+        }
+        totways = 0;
+
+        for (i = 0; i < numbers; i++)
+            totways += ways[chainlen % 2][i];
+
+        printf("%lld\n", totways);
+    }
+    return 0;
+}