send+more=money その4

# 漢字かななども使える（1 文字も可）バージョン
smm = function(str) {
    str = gsub("[ \t]", "", str)
    str = unlist(strsplit(str, ""))
    if (grepl(str[1], "+-")) {
        stop("Unary minus or plus is invalid.")
    }
    str = c(str, ".")
    nChar = length(str)
    operatorPosition = NULL
    for (i in seq_len(nChar)) {
        if (match(str[i], c("+", "-", "=", "."), 0) != 0) {
            operatorPosition = c(operatorPosition, i)
        }
    }
    nTerm = length(operatorPosition)
    word = vector("list", nTerm)
    op = rep("+", nTerm + 1)
    start = 1
    for (i in seq_len(nTerm)) {
        position = operatorPosition[i]
        word[[i]] = str[start:(position - 1)]
        op[i + 1] = str[position]
        start = position + 1
    }
    charSet = unique(unlist(word))
    if (length(charSet) > 10) {
        stop("Too many characters.")
    }
    library(e1071)
    perm = t(e1071::permutations(10) - 1)
    term = matrix(0, nTerm, ncol(perm))
    nonZeroTop = rep(TRUE, ncol(perm))
    for (i in seq_len(nTerm)) {
        subscript = match(word[[i]], charSet)
        term[i, ] = colSums(10^(length(subscript):1-1) * matrix(perm[subscript, ], ncol=ncol(perm)))
        if (op[i] == "-") {
            term[i, ] = -term[i, ]
        }
        nonZeroTop = nonZeroTop & perm[subscript[1], ] != 0
    }
    leftsideTerm = colSums(term[1:(nTerm - 1), ])
    answerFlag = leftsideTerm == term[nTerm, ] & nonZeroTop
    ans = unique(t(term[, answerFlag]))
    if (nrow(ans) == 0) {
        "No solution."
    } else if (nrow(ans) == 1) {
        op = op[-nTerm-1]
        op[1] = ""
        cat(gsub("--", "-", paste(op, ans, collapse="", sep="")))
    } else {
        ans
    }
}

> smm("すももと+ももとは=ともだちだ")
9771+7713=17484

> smm("言葉たす+言葉たす言葉+言葉をたす=ふくめんざん")
6519+651965+65819=724303

> smm("ははの+ははは+ばあば+ちちの+ちちは=じいじ") # 自作
226+222+303+116+112=979