title: Count Distinct Occurrences As A Subsequence
signature: func countDistinctOccurrencesAsASubsequence(s string, t string) int {
test_code: package main
  
  import (
      "fmt"
      "reflect"
      "math"
      "sort"
  )
  
  // SOLUTION CODE
  // ===================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE
  // ===================================
  func validateSolution(actual int, expected int) bool {
      return reflect.DeepEqual(actual,expected)
  }
  
  func driver(s string, t string, expected int) string {
      if validateSolution(PLACEHOLDER_FN_NAME(s, t),expected) {
              return "PASSED"
      }
      return "FAILED"
  
  }
  
  func main() {
  
      // Use imports to avoid undefined errors
      var _ = reflect.DeepEqual
      _ = math.Abs
      _ = sort.Sort
      result := ""
      result = driver("banana", 
  	"ban", 3)
      fmt.Printf("TEST-0...%s\n", result)
      
      result = driver("49597223", 
  	"42", 2)
      fmt.Printf("TEST-1...%s\n", result)
      
      result = driver("1000010000011", 
  	"010", 20)
      fmt.Printf("TEST-2...%s\n", result)
      
      result = driver("BTlzufK", 
  	"EpsVuzP lf", 0)
      fmt.Printf("TEST-3...%s\n", result)
      
      result = driver("3474007", 
  	"370", 2)
      fmt.Printf("TEST-4...%s\n", result)
      
      result = driver("0010", 
  	"00000", 0)
      fmt.Printf("TEST-5...%s\n", result)
      
      result = driver("dKHhoTD", 
  	"doT", 1)
      fmt.Printf("TEST-6...%s\n", result)
      
      result = driver("9123259723", 
  	"123", 4)
      fmt.Printf("TEST-7...%s\n", result)
      
      result = driver("11001000111110", 
  	"0", 6)
      fmt.Printf("TEST-8...%s\n", result)
      
      result = driver("iY WJlIZ", 
  	"iI", 1)
      fmt.Printf("TEST-9...%s\n", result)
      
          
  }
source_py: def count_distinct_occurrences_as_a_subsequence(S, T):
      m = len(T)
      n = len(S)
      if (m > n):
          return 0
      mat = [[0 for _ in range((n + 1))] for __ in range((m + 1))]
      for i in range(1, (m + 1)):
          mat[i][0] = 0
      for j in range((n + 1)):
          mat[0][j] = 1
      for i in range(1, (m + 1)):
          for j in range(1, (n + 1)):
              if (T[(i - 1)] != S[(j - 1)]):
                  mat[i][j] = mat[i][(j - 1)]
              else:
                  mat[i][j] = (mat[i][(j - 1)] + mat[(i - 1)][(j - 1)])
      return mat[m][n]
source_cpp: int count_distinct_occurrences_as_a_subsequence(string S, string T) {
    int m = T . length ( ), n = S . length ( );
    if ( m > n ) return 0;
    int mat [ m + 1 ] [ n + 1 ];
    for ( int i = 1;
    i <= m;
    i ++ ) mat [ i ] [ 0 ] = 0;
    for ( int j = 0;
    j <= n;
    j ++ ) mat [ 0 ] [ j ] = 1;
    for ( int i = 1;
    i <= m;
    i ++ ) {
      for ( int j = 1;
      j <= n;
      j ++ ) {
        if ( T [ i - 1 ] != S [ j - 1 ] ) mat [ i ] [ j ] = mat [ i ] [ j - 1 ];
        else mat [ i ] [ j ] = mat [ i ] [ j - 1 ] + mat [ i - 1 ] [ j - 1 ];
      }
    }
    return mat [ m ] [ n ];
  }