#include <stdio.h>
#include <stdlib.h>

/*
 * For grammar: (https://en.wikipedia.org/wiki/Recursive_ascent_parser)
 *   expr : expr '+' term   { $$ = $1 + $3; }
 *        | expr '-' term   { $$ = $1 - $3; }
 *        | term            { $$ = $1; }
 *        ;
 *
 *   term : '(' expr ')'    { $$ = $2; }
 *        | num             { $$ = $1; }
 *        ;
 *
 *   num : '0'              { $$ = 0; }
 *       | '1'              { $$ = 1; }
 *       ;
 */

#pragma GCC diagnostic ignored "-Wunused-value"

#define DIE(...) (printf("ERROR %s:%d\n", __FILE__, __LINE__), __VA_OPT__(exit(__VA_ARGS__),) exit(1), 1)

enum nonterminal { EXPR, TERM, NUM };
struct result { enum nonterminal nonterm; int value; int depth; char *s; };

struct args   { int args[2]; };
#define new_arg(...) (struct args){{__VA_ARGS__}}
#define get_arg(a, n) ((a).args[n])

struct result state0(char *s, struct args a);
struct result state1(char *s, struct args a);
struct result state2(char *s, struct args a);
struct result state3(char *s, struct args a);
struct result state4(char *s, struct args a);
struct result state5(char *s, struct args a);
struct result state6(char *s, struct args a);
struct result state7(char *s, struct args a);
struct result state8(char *s, struct args a);
struct result state9(char *s, struct args a);
struct result state10(char *s, struct args a);
struct result state11(char *s, struct args a);
struct result state12(char *s, struct args a);
struct result state13(char *s, struct args a);

int main(void)
{
    char *s = "1-((0-1)+1+1+1+1+1)-0+1-(((1)))+1+1+1-1+0+(1-0+1)-1-0";
    struct result r = state0(s, new_arg(0));
    printf("%s = %d\n", s, r.value);
    return 0;
}

/*
 * 0 $accept: . expr $end
 *
 * '('  shift, and go to state 1
 * '0'  shift, and go to state 2
 * '1'  shift, and go to state 3
 *
 * expr  go to state 4
 * term  go to state 5
 * num   go to state 6
 */
struct result state0(char *s, struct args a)
{
    struct result r = {0};
    switch(*s) {
    case '(': r = state1(s+1, a); break;
    case '0': r = state2(s+1, a); break;
    case '1': r = state3(s+1, a); break;
    default: DIE();
    }

    while(r.depth == 0) {
        switch(r.nonterm) {
        case EXPR: r = state4(r.s, new_arg(r.value)); break;
        case TERM: r = state5(r.s, new_arg(r.value)); break;
        case NUM:  r = state6(r.s, new_arg(r.value)); break;
        default: DIE();
        }
    }

    r.depth--;
    return r;
}

/*
 * 4 term: '(' . expr ')'
 *
 * '('  shift, and go to state 1
 * '0'  shift, and go to state 2
 * '1'  shift, and go to state 3
 *
 * expr  go to state 7
 * term  go to state 5
 * num   go to state 6
 */
struct result state1(char *s, struct args a)
{
    struct result r = {0};
    switch(*s) {
    case '(': r = state1(s+1, a); break;
    case '0': r = state2(s+1, a); break;
    case '1': r = state3(s+1, a); break;
    default: DIE();
    }

    while(r.depth == 0) {
        switch(r.nonterm) {
        case EXPR: r = state7(r.s, new_arg(r.value)); break;
        case TERM: r = state5(r.s, new_arg(r.value)); break;
        case NUM:  r = state6(r.s, new_arg(r.value)); break;
        default: DIE();
        }
    }

    r.depth--;
    return r;
}

/*
 * 6 num: '0' .
 *
 * $default  reduce using rule 6 (num)
 */
struct result state2(char *s, struct args a)
{
    (void)a;
    return (struct result){NUM, 0, 0, s};
}

/*
 * 7 num: '1' .
 *
 * $default  reduce using rule 7 (num)
 */
struct result state3(char *s, struct args a)
{
    (void)a;
    return (struct result){NUM, 1, 0, s};
}

/*
 * 0 $accept: expr . $end
 * 1 expr: expr . '+' term
 * 2     | expr . '-' term
 *
 * $end  shift, and go to state 8
 * '+'   shift, and go to state 9
 * '-'   shift, and go to state 10
 */
struct result state4(char *s, struct args a)
{
    struct result r = {0};
    switch(*s) {
    case '\0': r = state8(s+1,  a); break;
    case '+':  r = state9(s+1,  a); break;
    case '-':  r = state10(s+1, a); break;
    default: DIE();
    }

    (r.depth == 0) && DIE();

    r.depth--;
    return r;
}

/*
 * 3 expr: term .
 *
 * $default  reduce using rule 3 (expr)
 */
struct result state5(char *s, struct args a)
{
    return (struct result){EXPR, get_arg(a, 0), 0, s};
}

/*
 * 5 term: num .
 *
 * $default  reduce using rule 5 (term)
 */
struct result state6(char *s, struct args a)
{
    return (struct result){TERM, get_arg(a, 0), 0, s};
}

/*
 * 1 expr: expr . '+' term
 * 2     | expr . '-' term
 * 4 term: '(' expr . ')'
 *
 * '+'  shift, and go to state 9
 * '-'  shift, and go to state 10
 * ')'  shift, and go to state 11
 */
struct result state7(char *s, struct args a)
{
    struct result r = {0};
    switch(*s) {
    case '+': r = state9(s+1,  a); break;
    case '-': r = state10(s+1, a); break;
    case ')': r = state11(s+1, a); break;
    default: DIE();
    }

    (r.depth == 0) && DIE();

    r.depth--;
    return r;
}

/*
 * 0 $accept: expr $end .
 *
 * $default  accept
 */
struct result state8(char *s, struct args a)
{
    return (struct result){EXPR, a.args[0], 2, s};
}

/*
 * 1 expr: expr '+' . term
 *
 * '('  shift, and go to state 1
 * '0'  shift, and go to state 2
 * '1'  shift, and go to state 3
 *
 * term  go to state 12
 * num   go to state 6
 */
struct result state9(char *s, struct args a)
{
    struct result r = {0};
    switch(*s) {
    case '(': r = state1(s+1, a); break;
    case '0': r = state2(s+1, a); break;
    case '1': r = state3(s+1, a); break;
    default: DIE();
    }

    while(r.depth == 0) {
        switch(r.nonterm) {
        case TERM: r = state12(r.s, new_arg(r.value, get_arg(a, 0))); break;
        case NUM:  r = state6(r.s,  new_arg(r.value)); break;
        default: DIE();
        }
    }

    r.depth--;
    return r;
}

/*
 * 2 expr: expr '-' . term
 *
 * '('  shift, and go to state 1
 * '0'  shift, and go to state 2
 * '1'  shift, and go to state 3
 *
 * term  go to state 13
 * num   go to state 6
 */
struct result state10(char *s, struct args a)
{
    struct result r = {0};
    switch(*s) {
    case '(': r = state1(s+1, a); break;
    case '0': r = state2(s+1, a); break;
    case '1': r = state3(s+1, a); break;
    default: DIE();
    }

    while(r.depth == 0) {
        switch(r.nonterm) {
        case TERM: r = state13(r.s, new_arg(get_arg(a, 0), r.value)); break;
        case NUM:  r = state6(r.s,  new_arg(r.value)); break;
        default: DIE();
        }
    }

    r.depth--;
    return r;
}

/*
 * 4 term: '(' expr ')' .
 *
 * $default  reduce using rule 4 (term)
 */
struct result state11(char *s, struct args a)
{
    return (struct result){TERM, get_arg(a, 0), 2, s};
}

/*
 * 1 expr: expr '+' term .
 *
 * $default  reduce using rule 1 (expr)
 */
struct result state12(char *s, struct args a)
{
    return (struct result){EXPR, get_arg(a, 0) + get_arg(a, 1), 2, s};
}

/*
 * 2 expr: expr '-' term .
 *
 * $default  reduce using rule 2 (expr)
 */
struct result state13(char *s, struct args a)
{
    return (struct result){EXPR, get_arg(a, 0) - get_arg(a, 1), 2, s};
}