From 582542e39f1930c854c73d53744a8d4e369a7cf9 Mon Sep 17 00:00:00 2001
From: gonzo <gonzo@toniatuh.com>
Date: Fri, 19 May 2023 10:31:51 +0200
Subject: initial commit, contract struct + bullet loan

---
 Makefile      | 45 +++++++++++++++++++++++++++++++++++++++++++++
 bullet_loan.c | 31 +++++++++++++++++++++++++++++++
 contract.h    | 12 ++++++++++++
 loans.h       |  8 ++++++++
 4 files changed, 96 insertions(+)
 create mode 100644 Makefile
 create mode 100644 bullet_loan.c
 create mode 100644 contract.h
 create mode 100644 loans.h

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..a4b2611
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,45 @@
+UNAME := $$( uname -s )
+
+.if ${UNAME} == "Linux"
+CC=clang --std=gnu99
+.else
+CC=clang --std=c99
+.endif
+AR=ar ruvcs
+
+CFLAGS=-Wall -Wextra -Werror -Weverything -Wpadded -pedantic
+LIBS=-lncurses
+BLDFLAGS=-g
+RELFLAGS=-O2
+
+TARGET=lc
+DEPS=main.c
+HEAD=
+OBJ=${DEPS:.c=.o}
+
+LIB=las.a
+LDEPS=bullet_loan.c
+LHEAD=contract.h loans.h
+LOBJ=${LDEPS:.c=.o}
+
+.PHONY: all clean release $(TARGET) $(LIB)
+
+all: $(LIB) $(TARGET)
+
+$(OBJ): $(HEAD)
+$(LOBJ): $(LHEAD)
+
+%.o: %.c
+	$(CC) -o ./src/$@ -c $< $(CFLAGS)
+
+$(TARGET): $(OBJ) $(LIB)
+	$(CC) -o $@ $(OBJ) $(LIB) $(LIBS) $(BLDFLAGS)
+
+$(LIB): $(LOBJ)
+	$(AR) $(LIB) $(LOBJ)
+
+release: $(OBJ)
+	$(CC) -o $(TARGET) $(OBJ) $(LIBS) $(RELFLAGS)
+
+clean:
+	rm -f *.o *~ *.core $(OBJ) $(TARGET)
diff --git a/bullet_loan.c b/bullet_loan.c
new file mode 100644
index 0000000..189ca05
--- /dev/null
+++ b/bullet_loan.c
@@ -0,0 +1,31 @@
+#include "loans.h"
+
+contract *bullet_init(int n, int d, float r, float P) {
+	if ((n < 0)) return NULL;
+	if ((d > n)||(d < 0)) return NULL;
+	contract *c = (contract *)calloc(1, sizeof(contract));
+	c->n = (unsigned int)n;
+	c->d = (unsigned int)d;
+	c->r = r;
+	c->P = P;
+
+	return c;
+}
+
+float bullet_update(contract *c) {
+	if (c->k > c->n)
+		return 0.0f;
+	c->k++;
+	c->I = c->r * c->P;
+	if (c->k == c->n) {
+		c->D = c->P;
+		c->P = 0.0f;
+	}
+	c->A = c->D + c->I;
+
+	return c->A;
+}
+
+void bullet_free(contract *c) {
+	free(c);
+}
diff --git a/contract.h b/contract.h
new file mode 100644
index 0000000..4c74cb0
--- /dev/null
+++ b/contract.h
@@ -0,0 +1,12 @@
+#pragma once
+
+typedef struct contract {
+	unsigned int n; /* duration of the loan */
+	unsigned int k; /* current year */
+	unsigned int d; /* delay period of the loan */
+	float r; /* interest rate */
+	float P; /* part of the pricipal left at year k */
+	float I; /* the interest for year k */
+	float D; /* part of the capital reinbursed on year k */
+	float A; /* annuity for year k */
+} contract;
diff --git a/loans.h b/loans.h
new file mode 100644
index 0000000..8d99de7
--- /dev/null
+++ b/loans.h
@@ -0,0 +1,8 @@
+#pragma once
+#include <stdlib.h>
+#include "contract.h"
+
+/**** BULLET LOAN ****/
+contract *bullet_init(int n, int d, float r, float P);
+float bullet_update(contract *);
+void bullet_free(contract *c);
-- 
cgit v1.2.3