#/***********************************************************
#    sosrh.rb -- 自己組織化探索
#***********************************************************/
# 置換法 

NOT_FOUND = (-1)

def sosrch(x, a,  imin,  imax)
    if (imin > imax); return NOT_FOUND; end
    a[imax + 1] = x;  # 番人 
    i = imin;  while (a[i] != x); i += 1; end
    if (i > imax); return NOT_FOUND; end
    if (i != imin) 
        a[i] = a[i - 1];  i -= 1;  a[i] = x;  # 一つ前と交換 
    end
    return i
end

N = 8

a = []

for i in 0...N; a[i] = (rand * 100 + 1).to_i; end
while (true) 
    for i in 0...N; printf("  a[%d]=%d", i, a[i]); end
    printf("\nどれを探しますか? ")
    x = gets.to_i;  if (x < 0); break; end
    i = sosrch(x, a, 0, N - 1)
    if (i != NOT_FOUND); printf("i = %d\n", i)
    else printf("見つかりません.\n"); end
end

exit 0