题目描述

代码展示

#include <iostream>
#include <vector>using namespace std;bool cmp(vector<int> &A, vector<int> &B)
{if (A.size() != B.size()) return A.size() > B.size();for (int i = A.size() - 1; i >= 0; i -- )if (A[i] != B[i])return A[i] > B[i];return true;
}vector<int> sub(vector<int> &A, vector<int> &B)
{vector<int> C;for (int i = 0, t = 0; i < A.size(); i ++ ){t = A[i] - t;if (i < B.size()) t -= B[i];C.push_back((t + 10) % 10);if (t < 0) t = 1;else t = 0;}while (C.size() > 1 && C.back() == 0) C.pop_back();return C;
}int main()
{string a, b;vector<int> A, B;cin >> a >> b;for (int i = a.size() - 1; i >= 0; i -- ) A.push_back(a[i] - '0');for (int i = b.size() - 1; i >= 0; i -- ) B.push_back(b[i] - '0');vector<int> C;if (cmp(A, B)) C = sub(A, B);else C = sub(B, A), cout << '-';for (int i = C.size() - 1; i >= 0; i -- ) cout << C[i];cout << endl;return 0;
}