Overloaded mode function to support i64 (#1558)

Added a test.

Author: tareknaser

integration_tests/test_statistics.py

@@ -213,6 +213,11 @@ def test_mode():
     k = mode(d)
     assert k == -3
 
+    e: list[i64]
+    e = [i64(-1), i64(2), i64(-3), i64(-5), i64(-3), i64(-1), i64(4), i64(-2), i64(4), i64(-5), i64(-3), i64(4), i64(-3)]
+    l: i64 = mode(e)
+    assert l == i64(-3)
+
 
 def check():
     test_mean()

src/runtime/statistics.py

@@ -222,6 +222,7 @@ def harmonic_mean(x: list[f64]) -> f64:
 
 
 # TODO: Use generics to support other types.
+@overload
 def mode(x: list[i32]) -> i32:
     k: i32 = len(x)
     c: i32
@@ -243,6 +244,29 @@ def mode(x: list[i32]) -> i32:
             ans = x[c]
     return ans
 
+@overload
+def mode(x: list[i64]) -> i64:
+    k: i32 = len(x)
+    c: i32
+    count: dict[i64, i32] = {i64(0): 0}
+
+    # insert keys in the dictionary
+    for c in range(k):
+        count[x[c]] = 0
+
+    # update the frequencies
+    for c in range(k):
+        count[x[c]] = count[x[c]] + 1
+
+    max_count: i32 = 0
+    ans: i64
+    for c in range(k):
+        if max_count < count[x[c]]:
+            max_count = count[x[c]]
+            ans = x[c]
+    return ans
+
+
 @overload
 def variance(x: list[f64]) -> f64:
     """