fix: update cpp solutions to lc problem: No.3153 (#3462)

Author: yanglbme

solution/3100-3199/3153.Sum of Digit Differences of All Pairs/README.md

@@ -143,7 +143,7 @@ public:
                 nums[i] /= 10;
             }
             for (int i = 0; i < 10; ++i) {
-                ans += 1LL * (cnt[i] * (n - cnt[i]));
+                ans += 1LL * cnt[i] * (n - cnt[i]);
             }
         }
         return ans / 2;

solution/3100-3199/3153.Sum of Digit Differences of All Pairs/README_EN.md

@@ -141,7 +141,7 @@ public:
                 nums[i] /= 10;
             }
             for (int i = 0; i < 10; ++i) {
-                ans += 1LL * (cnt[i] * (n - cnt[i]));
+                ans += 1LL * cnt[i] * (n - cnt[i]);
             }
         }
         return ans / 2;

solution/3100-3199/3153.Sum of Digit Differences of All Pairs/Solution.cpp

@@ -12,9 +12,9 @@ class Solution {
                 nums[i] /= 10;
             }
             for (int i = 0; i < 10; ++i) {
-                ans += 1LL * (cnt[i] * (n - cnt[i]));
+                ans += 1LL * cnt[i] * (n - cnt[i]);
             }
         }
         return ans / 2;
     }
-};
+};