// 易错点4：仅处理栈非空的情况，忽略栈空的情况 → 栈空时res[i]会是undefined
build-index renders all 1,418 source characters and 34 target characters as 48x48 greyscale PNGs, one per font that natively contains the character. Fontconfig is queried per-character to avoid brute-force rendering across all 230 fonts (97% reduction: 8,881 targeted renders vs 326,140 brute-force).
，更多细节参见搜狗输入法下载
goal += pixel - candidate[n]
It seems a little wacky to modern sensibilities, but keep in mind that this was