#include <stdio.h>
#include <math.h>
#include <string.h>
 
// Global account structure
struct Account {
    char name[50];
    int accountNumber;
    float balance;
} user;
 
// Function prototypes
void createAccount();
void deposit();
void withdraw();
void checkBalance();
void calculateInterest();
float simpleInterest(float p, float r, float t);
float compoundInterest(float p, float r, float t);
 
int main() {
    int choice;
 
    printf("===== Welcome to Simple Bank System =====\n");
    createAccount();
 
    do {
        printf("\n===== Banking Menu =====\n");
        printf("1. Deposit Money\n");
        printf("2. Withdraw Money\n");
        printf("3. Check Balance\n");
        printf("4. Calculate Interest (SI / CI)\n");
        printf("0. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);
 
        switch(choice) {
            case 1: deposit(); break;
            case 2: withdraw(); break;
            case 3: checkBalance(); break;
            case 4: calculateInterest(); break;
            case 0: printf("\nThank you for using Simple Bank System!\n"); break;
            default: printf("\nInvalid choice! Please try again.\n");
        }
    } while(choice != 0);
 
    return 0;
}
 
// Create account function
void createAccount() {
    printf("\nEnter Account Holder Name: ");
    scanf(" %[^\n]s", user.name);
    printf("Enter Account Number: ");
    scanf("%d", &user.accountNumber);
    user.balance = 0.0;
    printf("\nAccount Created Successfully!\n");
}
 
// Deposit function
void deposit() {
    float amount;
    printf("\nEnter amount to deposit: ");
    scanf("%f", &amount);
    if(amount > 0) {
        user.balance += amount;
        printf("Amount %.2f deposited successfully!\n", amount);
    } else {
        printf("Invalid deposit amount!\n");
    }
}
 
// Withdraw function
void withdraw() {
    float amount;
    printf("\nEnter amount to withdraw: ");
    scanf("%f", &amount);
    if(amount > 0 && amount <= user.balance) {
        user.balance -= amount;
        printf("Amount %.2f withdrawn successfully!\n", amount);
    } else {
        printf("Invalid withdrawal amount or insufficient balance!\n");
    }
}
 
// Check balance function
void checkBalance() {
    printf("\nAccount Holder: %s\n", user.name);
    printf("Account Number: %d\n", user.accountNumber);
    printf("Current Balance: %.2f\n", user.balance);
}
 
// Calculate interest function
void calculateInterest() {
    float rate, time, si, ci;
    int choice;
 
    printf("\nEnter Rate of Interest (in %%): ");
    scanf("%f", &rate);
    printf("Enter Time (in years): ");
    scanf("%f", &time);
 
    printf("\n1. Simple Interest\n2. Compound Interest\nEnter your choice: ");
    scanf("%d", &choice);
 
    if(choice == 1) {
        si = simpleInterest(user.balance, rate, time);
        printf("\nSimple Interest on current balance = %.2f\n", si);
    } else if(choice == 2) {
        ci = compoundInterest(user.balance, rate, time);
        printf("\nCompound Interest on current balance = %.2f\n", ci);
    } else {
        printf("Invalid choice!\n");
    }
}
 
// Function to calculate SI
float simpleInterest(float p, float r, float t) {
    return (p * r * t) / 100;
}
 
// Function to calculate CI
float compoundInterest(float p, float r, float t) {
    float amount = p * pow((1 + r / 100), t);
    return amount - p;
}