Cod sursa(job #2786530)

Utilizator LucaMihaiLM10Luca Ilie LucaMihaiLM10 Data 21 octombrie 2021 09:51:34
Problema Arbori indexati binar Scor 50
Compilator c-64 Status done
Runda Arhiva educationala Marime 1.41 kb
#include <stdio.h>

#define MAX_N 100000
#define MAX_LOG 17

int aib[MAX_N + 1];

void update( int i, int a, int n ) {
    while ( i <= n ) {
        aib[i] += a;
        i += i & -i;
    }
}

int query( int i ) {
    int s;

    s = 0;
    while ( i > 0 ) {
        s += aib[i];
        i -= i & -i;
    }

    return s;
}

int main() {
    FILE *fin, *fout;
    int n, q, tip, a, s, f, p, sum, pas, i;

    fin = fopen( "aib.in", "r" );

    fscanf( fin, "%d%d", &n, &q );
    for ( i = 1; i <= n; i++ ) {
        fscanf( fin, "%d", &a );
        update( i, a, n );
    }

    fout = fopen( "aib.out", "w" );

    for ( i = 0; i < q; i++ ) {
        fscanf( fin, "%d", &tip );
        if ( tip == 0 ) {
            fscanf( fin, "%d%d", &p, &a );
            update( p, a, n );
        }
        else if ( tip == 1 ) {
            fscanf( fin, "%d%d", &s, &f );
            fprintf( fout, "%d\n", query( f ) - query( s - 1 ) );
        }
        else {
            fscanf( fin, "%d", &s );

            sum = 0;
            pas = (1 << MAX_LOG);
            p = 0;
            while ( pas > 0 ) {
                if ( p + pas <= n && sum + aib[p + pas] <= s ) {
                    p += pas;
                    sum += aib[p];
                }
                pas >>= 1;
            }

            fprintf( fout, "%d\n", sum == s ? p : -1 );
        }
    }

    return 0;
}