USACO zerosum

/*
ID: david.h2
LANG: C++11
TASK: zerosum
*/

#include <iostream>
#include <vector>

using namespace std;

FILE *fout = fopen("zerosum.out", "w");

int n;
vector<int> currentsequence(8, -1);

void test(int left) {
    if (left == 0) {
        vector<int> digits(n, 0);
        digits[0] = 1;
        int i = 0;
        int opi = 0;
        for (int digit = 2; digit <= n; digit++) {
            if (currentsequence[opi] == 0) {
                digits[i] *= 10;
                digits[i] += digit;
            } else {
                i++;
                digits[i] = digit;
            }
            opi++;
        }
        int w = digits[0];
        int currdigit = 1;
        for (int op = 0; op < n - 1; op++) {
            if (digits[currdigit] == 0) {
                break;
            }
            if (currentsequence[op] == 0) {
                continue;
            }
            if (currentsequence[op] == 1) {
                w += digits[currdigit];
            } else if (currentsequence[op] == 2) {
                w -= digits[currdigit];
            }
            currdigit++;
        }
        if (w == 0) {
            fprintf(fout, "%d", 1);
            for (int p = 2; p <= n; p++) {
                if (currentsequence[p - 2] == 0) {
                    fprintf(fout, "%c", ' ');
                } else if (currentsequence[p - 2] == 1) {
                    fprintf(fout, "%c", '+');
                } else if (currentsequence[p - 2] == 2) {
                    fprintf(fout, "%c", '-');
                }
                fprintf(fout, "%d", p);
            }
            fprintf(fout, "\n");
        }
        return;
    }
    for (int new_op = 0; new_op <= 2; new_op++) {
        currentsequence[n - left - 1] = new_op;
        test(left - 1);
    }
}

int main() {
    FILE *fin = fopen("zerosum.in", "r");
    fscanf(fin, "%d", &n);
    test(n - 1);
    return 0;
}