50087. See-Saw

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

int n;
int w[2055];
int s = 0;

int find_pt(){
    int l = 0, r = 0;
    int l_bucket = 0, r_bucket = 0;
    for(int i = 1; i < n; i++) r += (i) * w[i];
    for(int i = 0; i < n; i++) r_bucket += w[i];

    int ptr = 0;
    while(1){
        if(l == r) return ptr;
        else if(l > r) return -1;

        l_bucket += w[ptr], r_bucket -= w[ptr];
        l += l_bucket, r -= r_bucket;
        ptr++;
    }
    return -1;
}

int main(){
    scanf("%d", &n);
    for(int i = 0; i < n; i++) scanf("%d", &w[i]);
    while(1){
        int rtv = find_pt();
        if(rtv != -1){
            printf("%d", w[0]);
            for(int i = 1; i < n; i++){
                if(i != rtv) printf(" %d", w[i]);
                else printf(" v");
            }
            break;
        }


        int temp = w[s];
        w[s] = w[n - s - 1];
        w[n - s - 1] = temp;
        s++;
    }
    printf("\n");
}