huawei2021.js

const P = "BC";
const B = "AAABBBBCCCCBBB";

console.log(`P=${P}\nB=${B}`);

function testB(b) {
  if (!b) return 0;
  if (b.length < 3) return -1;
  let min = -2;
  let s = 0;
  for (let i = 1; i < b.length; ++i) {
    if (b[s] != b[i]) {
      if (i - s > 2) {
        const rest = b.substring(0, s) + b.substring(i);
        const c = testB(rest);
        if (c > 0)
          min = min == -2 || min > c ? c : min;
      }
      s = i;
    }
  }
  if (s == 0) return 1;
  return min + 1;
}

function testP(p, b) {
  if (!p) return testB(b);
  let min = -1;
  for (let i = 0; i < b.length - p.length + 1; ++i) {
    if (b[i] == p[0]) {
      const left = testB(b.substring(0, i))
      const right = testP(p.substring(1), b.substring(i + 1));
      if (left >= 0 && right >= 0) {
        const c = left + right;
        console.log(`${c}=${left}+${right} ${b.substring(0, i)}-${b[i]}-${b.substring(i + 1)}`);
        min = min == -1 || min > c ? c : min;
      }
    }
  }
  return min;
}

console.log(testP(P, B));