diff --git a/2025.04.18/02Ex/Makefile b/2025.04.18/02Ex/Makefile new file mode 100644 index 0000000..b4045b2 --- /dev/null +++ b/2025.04.18/02Ex/Makefile @@ -0,0 +1,42 @@ +WFLAGS = -fstack-protector-all -W -Wall -Wextra -Wunused \ +-Wempty-body -Wlogical-op -Wold-style-declaration -Wmissing-parameter-type \ +-Wignored-qualifiers -Winit-self -Wshadow -Wtype-limits \ +-Wpointer-arith -Wformat-security -Wmissing-format-attribute -Wformat=1 \ +-Wdeclaration-after-statement -Wbad-function-cast -Wnested-externs \ +-Wmissing-prototypes -Wmissing-declarations -Wold-style-definition \ +-Wcast-align -Werror -pedantic -pedantic-errors -Wfloat-equal \ +-Wwrite-strings -Wno-long-long -std=gnu99 -Wstrict-prototypes \ +-Wmissing-field-initializers -Wpointer-sign + +CFLAGS = -std=gnu99 -mfpmath=sse -O3 + +ifeq ($(OS),Windows_NT) + EXE = exe + CLEAN = del + LFLAGS = -lssp -lm +else + EXE = out + CLEAN = rm -f + LFLAGS = -lm +endif + +TARGET = a02.$(EXE) +OBJ = main.o solve.o array_io.o + +%.o: %.c + gcc $(CFLAGS) $(WFLAGS) -c $< -o $@ + +$(TARGET): $(OBJ) + gcc $^ -o $@ $(LFLAGS) + +# Отладочная сборка (gdb) +gdb: CFLAGS = -mfpmath=sse -std=gnu99 -g -O0 +gdb: clean $(TARGET) + +# Профилировочная сборка (gprof) +prof: CFLAGS = -std=gnu99 -mfpmath=sse -pg -O3 +prof: LFLAGS = -lm -pg +prof: clean $(TARGET) + +clean: + $(CLEAN) *.o *$(EXE) diff --git a/2025.04.18/02Ex/array_io.c b/2025.04.18/02Ex/array_io.c new file mode 100644 index 0000000..780f0a3 --- /dev/null +++ b/2025.04.18/02Ex/array_io.c @@ -0,0 +1,26 @@ +#include +#include +#include "array_io.h" + +io_status read_values (double * restrict X, double * restrict Y, const int n, const char * restrict name) +{ + FILE *fp; + if (!(fp = fopen(name, "r"))) + return ERROR_OPEN; + + for (int i = 0; i < n; ++i) + if (fscanf(fp, "%lf\t%lf", X + i, Y + i) != 2) + { fclose(fp); return ERROR_READ; } + + fclose(fp); + return SUCCESS; +} + +void print_values (const double * restrict X, const double * restrict Y, const int n, const int p) +{ + int np = (n > p ? p : n); + + for (int i = 0; i < np; i++) + printf("f(%lf) = %lf\n", X[i], Y[i]); +} + diff --git a/2025.04.18/02Ex/array_io.h b/2025.04.18/02Ex/array_io.h new file mode 100644 index 0000000..7a0ce14 --- /dev/null +++ b/2025.04.18/02Ex/array_io.h @@ -0,0 +1,9 @@ +#ifndef ARRAY_IO_H +#define ARRAY_IO_H + +#include "io_status.h" + +io_status read_values (double * restrict X, double * restrict Y, const int n, const char * restrict name); +void print_values (const double * restrict X, const double * restrict Y, const int n, const int p); + +#endif diff --git a/2025.04.18/02Ex/io_status.h b/2025.04.18/02Ex/io_status.h new file mode 100644 index 0000000..778a4a1 --- /dev/null +++ b/2025.04.18/02Ex/io_status.h @@ -0,0 +1,15 @@ +#ifndef IO_STATUS_H +#define IO_STATUS_H + +#define ERR_MEM "Error: Not enough memory!" +#define ERR_OPEN "Error: Cannot open file" +#define ERR_READ "Error: Cannot read file" + +typedef enum _io_status +{ + SUCCESS, + ERROR_OPEN, + ERROR_READ +} io_status; + +#endif diff --git a/2025.04.18/02Ex/main.c b/2025.04.18/02Ex/main.c new file mode 100644 index 0000000..4e8ed94 --- /dev/null +++ b/2025.04.18/02Ex/main.c @@ -0,0 +1,73 @@ +#include +#include +#include + +#include "array_io.h" +#include "io_status.h" +#include "solve.h" + +/* ./a.out x_0 n filename */ +int main(int argc, char *argv[]) +{ + double x_0, t, r = 0, *X = 0, *Y = 0; + int n, task = 2; + char *name = 0; + io_status ret; + + if ( + !((argc == 4) && + sscanf(argv[1], "%lf", &x_0) == 1 && + ((sscanf(argv[2], "%d", &n) == 1) && n > 0) && + ((name = argv[3]) && name)) + ) { + fprintf(stderr, "Usage: %s x_0 n filename\n", argv[0]); + return 1; + } + + X = (double *)malloc(n * sizeof(double)); + if (!X) + { + fprintf(stderr, "%s\n", ERR_MEM); + return 2; + } + + Y = (double *)malloc(n * sizeof(double)); + if (!Y) + { + free(X); + fprintf(stderr, "%s\n", ERR_MEM); + return 2; + } + + ret = read_values(X, Y, n, name); + do { + switch (ret) + { + case SUCCESS: + continue; + case ERROR_OPEN: + fprintf(stderr, "%s '%s'!\n", ERR_OPEN, name); + break; + case ERROR_READ: + fprintf(stderr, "%s '%s'!\n", ERR_READ, name); + break; + } + + free(X); + free(Y); + + return 3; + } while (0); + + t = clock(); + r = t2_solve(x_0, n, X, Y); + t = (clock() - t) / CLOCKS_PER_SEC; + + printf("%s : Task = %d Result = %e Elapsed = %.2f\n", argv[0], task, r, t); + + free(X); + free(Y); + + return 0; +} + diff --git a/2025.04.18/02Ex/solve.c b/2025.04.18/02Ex/solve.c new file mode 100644 index 0000000..b2a7d51 --- /dev/null +++ b/2025.04.18/02Ex/solve.c @@ -0,0 +1,56 @@ +#include "solve.h" + +#include +#include +#include + +// the Newton interpolation polynomial +double t2_solve (const double x_0, const int n, const double * restrict X, double * restrict Y) +{ + double last_x = X[n-1]; + double last_y = Y[n-1]; + + double value = 0; + double start_value = 0; + + for (int k = 0; k < n-1; ++k) + { + printf ("------- K = %d -------\n", k); + + for (int i = n-2; i >= k; --i) + { + const double x_i = X[i-k]; + const double y_i = Y[i]; + + if (fabs(last_x - x_i) < DBL_EPSILON) + return DBL_MAX; + +// printf ("Y[%d] = (%lf - %lf) / (%lf - %lf)\n", i+1, last_y, y_i, last_x, x_i); + Y[i+1] = (last_y - y_i) / (last_x - x_i); + printf ("I = %d, f(x%d, ... , x%d) = %lf\n", i, i-k+1, i+2, Y[i]); + + last_x = x_i; + last_y = y_i; + } + + last_x = X[n-1]; + last_y = Y[n-1]; + } + + last_x = X[0]; + start_value = 1; + value = Y[0]; + + for (int i = 1; i < n; ++i) + { + start_value *= (x_0 - last_x); + if (fabs(Y[i]) > DBL_EPSILON) + value += Y[i] * start_value; + printf ("i = %d, start_value = %lf, value = %lf, last_x = %lf\n", i, start_value, value, last_x); + printf ("Y[%d] = %lf\n", i, Y[i]); + last_x = X[i]; + } + + return value; +} + diff --git a/2025.04.18/02Ex/solve.h b/2025.04.18/02Ex/solve.h new file mode 100644 index 0000000..054f3bc --- /dev/null +++ b/2025.04.18/02Ex/solve.h @@ -0,0 +1,6 @@ +#ifndef SOLVE_H +#define SOLVE_H + +double t2_solve (const double x_0, const int n, const double * restrict X, double * restrict Y); + +#endif