Add sorted permutation with repeats sultion

Math/SortedPermutationRankWithRepeats.cpp

@@ -0,0 +1,62 @@
+#define MOD 1000003
+long long int fact(int n) {
+    if (n == 0 || n == 1) {
+        return 1;
+    }
+    return (fact(n - 1) * n) % MOD;
+}
+ long long int inverseNumber(int num) {
+    long long int ans = 1, base = (long long) num;
+    int power = MOD - 2;
+    while (power > 0) {
+        if (power == 1) {
+            return (ans * base) % MOD;
+        }
+        if (power % 2 == 0) {
+            base = (base * base) % MOD;
+            power /= 2;
+        } else {
+            ans = (ans * base) % MOD;
+            power--;
+        }
+    }
+    return ans;
+}
+int Solution::findRank(string A) {
+    if (A.size() <= 0) {
+        return 0;
+    }
+    int alpha[52] = {0};
+    for (int i = 0; i < A.size(); i ++) {
+        if (islower(A[i])) {
+            alpha[A[i] - 'a' + 26] ++;
+        } else {
+            alpha[A[i] - 'A'] ++;
+        }
+    }
+    long long int total = 0;
+    for (int i = 0; i < A.size(); i ++) {
+        long long localCount = 0;
+        int size = islower(A[i]) ? A[i] - 'a' + 26 : A[i] - 'A';
+        long long int count = (fact(A.size() - i - 1));
+        for (int j = 0; j < size; j ++) {
+            if (alpha[j]) {
+                alpha[j] --;
+                localCount = count;
+                for (int k = 0; k < 52; k ++) {
+                    if (alpha[k]) {
+                        localCount = (localCount * inverseNumber(fact(alpha[k]))) % MOD;
+                    }
+                }
+                alpha[j] ++;
+                total = (total + localCount) % MOD;
+            }
+        }
+        if (islower(A[i])) {
+            alpha[A[i] - 'a' + 26] --;
+        } else {
+            alpha[A[i] - 'A'] --;
+        }
+    }
+    return (total + 1) % MOD;
+}