Data commit

Task/Sum-to-100/Modula-2/sum-to-100.mod2

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+MODULE SumTo100;
+FROM FormatString IMPORT FormatString;
+FROM Terminal IMPORT WriteString,WriteLn,ReadChar;
+
+PROCEDURE Evaluate(code : INTEGER) : INTEGER;
+VAR
+    value,number,power,k : INTEGER;
+BEGIN
+    value := 0;
+    number := 0;
+    power := 1;
+
+    FOR k:=9 TO 1 BY -1 DO
+        number := power * k + number;
+        IF code MOD 3 = 0 THEN
+            (* ADD *)
+            value := value + number;
+            number := 0;
+            power := 1
+        ELSIF code MOD 3 = 1 THEN
+            (* SUB *)
+            value := value - number;
+            number := 0;
+            power := 1
+        ELSE
+            (* CAT *)
+            power := power * 10
+        END;
+        code := code / 3
+    END;
+
+    RETURN value
+END Evaluate;
+
+PROCEDURE Print(code : INTEGER);
+VAR
+    expr,buf : ARRAY[0..63] OF CHAR;
+    a,b,k,p : INTEGER;
+BEGIN
+    a := 19683;
+    b := 6561;
+    p := 0;
+
+    FOR k:=1 TO 9 DO
+        IF (code MOD a) / b = 0 THEN
+            IF k > 1 THEN
+                expr[p] := '+';
+                INC(p)
+            END
+        ELSIF (code MOD a) / b = 1 THEN
+            expr[p] := '-';
+            INC(p)
+        END;
+
+        a := b;
+        b := b / 3;
+        expr[p] := CHR(k + 30H);
+        INC(p)
+    END;
+    expr[p] := 0C;
+
+    FormatString("%9i = %s\n", buf, Evaluate(code), expr);
+    WriteString(buf)
+END Print;
+
+(* Main *)
+CONST nexpr = 13122;
+VAR
+    i,j : INTEGER;
+    best,nbest,test,ntest,limit : INTEGER;
+    buf : ARRAY[0..63] OF CHAR;
+BEGIN
+    WriteString("Show all solution that sum to 100");
+    WriteLn;
+    FOR i:=0 TO nexpr-1 DO
+        IF Evaluate(i) = 100 THEN
+            Print(i)
+        END
+    END;
+    WriteLn;
+
+    WriteString("Show the sum that has the maximum number of solutions");
+    WriteLn;
+    nbest := -1;
+    FOR i:=0 TO nexpr-1 DO
+        test := Evaluate(i);
+        IF test > 0 THEN
+            ntest := 0;
+            FOR j:=0 TO nexpr-1 DO
+                IF Evaluate(j) = test THEN
+                    INC(ntest)
+                END;
+                IF ntest > nbest THEN
+                    best := test;
+                    nbest := ntest
+                END
+            END
+        END
+    END;
+    FormatString("%i has %i solutions\n\n", buf, best, nbest);
+    WriteString(buf);
+
+    WriteString("Show the lowest positive number that can't be expressed");
+    WriteLn;
+    FOR i:=0 TO 123456789 DO
+        FOR j:=0 TO nexpr-1 DO
+            IF i = Evaluate(j) THEN
+                BREAK
+            END
+        END;
+        IF i # Evaluate(j) THEN
+            BREAK
+        END
+    END;
+    FormatString("%i\n\n", buf, i);
+    WriteString(buf);
+
+    WriteString("Show the ten highest numbers that can be expressed");
+    WriteLn;
+    limit := 123456789 + 1;
+    FOR i:=1 TO 10 DO
+        best := 0;
+        FOR j:=0 TO nexpr-1 DO
+            test := Evaluate(j);
+            IF (test < limit) AND (test > best) THEN
+                best := test
+            END
+        END;
+        FOR j:=0 TO nexpr-1 DO
+            IF Evaluate(j) = best THEN
+                Print(j)
+            END
+        END;
+        limit := best
+    END;
+
+    ReadChar
+END SumTo100.