Finding an Element Using Minimum Segments in a Seven-Segment Display in C++

A seven-segment display is a form of electronic display device that uses seven individual segments to represent numerals and some alphabetic characters. Each of these segments is labelled with letters a through g. Liquid crystal displays, calculators, and electronic measurement devices often use seven-segment displays to show numbers.

Each segment in these displays forms digits ranging from zero to nine. The primary aim of this article is to determine the digit that requires the least number of segments to be displayed from a given set of numbers.

The segments used per digit are as follows:

From this table, we will see that digit 1 requires the fewest segments (2).

Problem Statement

Analyse which digit from zero to nine requires the least number of segments to form a seven-segment display. If there is a tie for the least number of segments, return the lowest digit value.

Seven-Segment Representation

Example 1:

Let us take an example to find an element using minimum segments in seven-segment display in C++.

Basic Iterative Approach:

1. Set up an array which stores the segment count for each digit.
2. Go through the provided set of digits and select the digit with the smallest segment count.
3. If there are two or more digits with the same segment count, select the one with the lowest value.

Code Implementation:

Output:

Digit using minimum segments: 1   

Explanation

• In this example, we define an array segmentCount[10] to store the segment count for each digit.
• The function findMinSegmentDigit():
  • Iterates through the given digits.
  • Tracks the minimum segment count and the smallest corresponding digit.
• The main() function initializes a sample vector of digits and calls findMinSegmentDigit() to determine the result.

Example 2:

Let us take another example to find an element using minimum segments in seven-segment display in C++.

Object-Oriented & Sorting Approach:

1. Store the segment count for each digit using an array.
2. Use a class to represent a digit with properties: value and segment count.
3. Sort the digits based on segment count and numerical value.
4. Use STL for efficient sorting.
5. Process dynamic input from the user.

Code Implementation:

Output:

Enter the number of digits: 6
Enter 6 digits (0-9): 3 5 7 1 9 0
Digit using minimum segments: 1   

Example 3:

Let us take another example to find an element using minimum segments in seven-segment display in C++.

Optimized Single-Pass Approach:

1. Precompute segment counts in an array for constant-time lookup.
2. Traverse the input list once to determine the digit with:
   • The minimum segment count.
   • The smallest numerical value in case of ties.
3. Return the result in O(n) time complexity.

Code Implementation:

Output:

Enter the number of digits: 6
Enter 6 digits (0-9): 3 5 7 1 9 0
Digit using minimum segments: 1   

Applications of Seven-Segment Displays:

Several applications of seven-segment displays in C++ are as follows:

1. Power Optimization in Battery-Powered Devices:

• Use case: Digital clocks, calculators, smart meters, and wristwatches utilize seven-segment displays.
• Benefit: Devices can display numbers with the least segments when possible, for example, 3 could be displayed as a 1 during lower battery life contexts.
• Example: A low-power mode in a calculator may choose certain contexts where 1 would be shown instead of 7 or 8, thereby reducing power consumption.

2. Cost-Effective Digital Signage

• Use case: LED billboards and electronic price tags at supermarkets.
• Benefit: Less actively used LED segments increase durability and allow for more cost efficiency as they extend use.
• Example: When dynamically adjusting prices, a gas station price board may prioritize numbers that use 1 or 0 during process to save time and reduce energy consumption.

3. Reduced Heat Generation in LED Displays

• Use case: Number displays for public transport, elevators, and industry counters.
• Benefit: There is a decrease in energy consumption due to reduced segment usage.
• Example: In an elevator display, when the segment is not required, pre-programmed messages will cause the LED to lower.

Advantages of Seven-Segment Displays:

Several advantages of seven-segment displays in C++ are as follows:

1. Lower power consumption and better energy efficiency

• When a device is in less active segments, functionality is optimised, and less energy is consumed and effective for power-supplied/multimedia devices such as digital clocks, smart watches, calculators, etc.

2. Device Longevity on The Rise

• Decreasing the active segments of display LEDs results in less heat being generated which increases the life span of the LED.
• It is beneficial for long-term traffic signage and industrial display purposes.
• Example: In display boards, when segments are not in use at a train station, LED panel life is extended to several years.

3. Great Performance Improvement for Low Power Draw Devices

• Power for microcontrollers, IoT devices, and systems have severe limitations for what they can consume.
• With the aid of two-segment numerals, the processing load on the system is reduced and system efficiency is maximized.
• Example: Fitness trackers and medical devices can sustain prolonged usage in low battery mode by enabling low-segment display settings.

Disadvantages of Seven-Segment Displays:

Several disadvantages of seven-segment displays in are as follows:

1. Readability and Aesthetics Problems

• When using fewer segments, numbers on big digital displays can be difficult to read.
• Some digits, like one, give the numeral fewer segments but do not have enough visual separation from the background.
• Example: In airport screens, reducing segments in numbers makes it harder to distinguish them from a distance.

2. Swap Approximate Displays’ Accuracy for Efficiency

• The approximation given in some cases for numeral display values may incur scenarios where pessimistic accuracy is heightened.
• Not appropriate in areas where countercases have to be shown (as in stock market boards or medical instruments).
• Example: Although 110 over 80 simply requires fewer segments to display than 120 over 80, a blood pressure monitor should never read eleven over ten.

3. Limitations of Fixed Segment Displays

• Circuitry for many seven-segment displays is hardwired, and hence, control of segment illumination is conscribed to set circuits.
• The older models do not have the flexibility to decrease the number of segments incorporated into a specific pattern, which may offer greater economy.
• Such patterns are witnessed in some cash registers and fuel pump displays and there is no way of changing Fixed Segment patterns.

Conclusion:

In conclusion, this article demonstrates how the design of seven-segment displays can be optimized by selecting digits that require the fewest segments. An optimization approach based on a lookup table with a precomputed segment count array provides an efficient solution. This method can also be beneficial in applications such as improving power efficiency in digital displays.