fixed gas expense issue by using mappings

[kairveeehh]

Storing large dynamic arrays directly in mappings can lead to gas limit issues, especially when the arrays grow too large. By using mappings of structs, we avoid the need for this linear-time iteration when adding, removing, or accessing elements and further gas costs are minimied because the operations required to add remove and access data are more efficient with mappings of structs compared to dynamic arrays directly stored in mappings. @jaibhedia

please review and merge

[kairveeehh]

@jaibhedia its been 5 days , please update me about it