leader.c

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

// zakladajac, ze tablica t[n] posiada element wystepujacy na wiecej niz polowie
// pozycji, wskazuje jego wartosc

int leader(int n, int t[]) {
    int candidate = t[0];
    int count = 1;
    for (int i = 1; i < n; ++i) {
        if (count == 0) {
            candidate = t[i];
            ++count;
        } else {  // count > 0
            if (t[i] == candidate)
                ++count;
            else
                --count;
        }
    }
    return candidate;
}

int main(void) {
    int n;
    if(!scanf("%d", &n)) printf("wrong input");

    int* t = (int*)malloc((unsigned)n * sizeof(int));
    for (int i = 0; i < n; ++i) if(!scanf("%d", &t[i])) printf("wrong input");

    printf("%d", leader(n, t));

    free(t);
    return 0;
}