vector下标溢出问题，已经用resize（）修改过了，还是溢出。

#include <iostream>
#include<fstream>
#include <string>
#include <stack>
#include<vector>
#include<chrono>

using namespace std;
using namespace chrono;

void lcsLength(string x, string y, vector< vector<int>>& c, vector< vector<char>>& b)
{
    int m = x.size();
    int n = y.size();
    /*c.push_back(m);
    b.push_back(n);*/
    c.resize(m + 10);
    b.resize(m + 10);
    for (int i = 0; i < c.size(); ++i)
         c[i].resize(n + 3);
    for (int i = 0; i < b.size(); ++i)
         b[i].resize(n + 10);

    for (size_t i = 0; i <= c.size() - 1; i++) {
        if (i >= c.size() || i < 0) {
            cout << "vetcor下标越界" << endl; break;
        }
        c[i].resize(n + 10);
    }
    for (size_t i = 0; i <= b.size() - 1; i++) {
        if (i >= b.size() || i < 0) {
            cout << "vetcor下标越界" << endl; break;
        }
        b[i].resize(n + 10);
    }
        

    for (size_t i = 1; i <= m; i++) {
        for (size_t j = 1; j <= n; j++) {
            if (x[i - 1] == y[j - 1]) {
                c[i][j] = c[i - 1][j - 1] + 1;
                b[i][j] = 'c';
            }
            else if (c[i - 1][j] >= c[i][j - 1]) {
                c[i][j] = c[i - 1][j];
                b[i][j] = 'u';
            }
            else {
                c[i][j] = c[i][j - 1];
                b[i][j] = 'l';
            }
        }
    }
}
void print_lcs(vector< vector<char>>& b, string x, size_t i, size_t j)
{
    if (i == 0 || j == 0)
        return;
    if (b[i][j] == 'c') {
        print_lcs(b, x, i - 1, j - 1);
        cout <<x[i - 1];
    }
    else if (b[i][j] == 'u')
        print_lcs(b, x, i - 1, j);
    else
        print_lcs(b, x, i, j - 1);
}
string gengerString(int n,string str) {
    srand((unsigned)time(NULL));                        //产生随机化种子
    /*printf("生成%d个字符的字符串\n", n);*/
    /*std::string str = "";*/
    for (int i = 1; i <= n; i++)
    {
        int flag;
        flag = rand() % 2;                     //随机使flag为1或0，为1就是大写，为0就是小写 
        if (flag == 1)                        //如果flag=1 
            str += rand() % ('Z' - 'A' + 1) + 'A';       //追加大写字母的ascii码 
        else
            str += rand() % ('z' - 'a' + 1) + 'a';       //如果flag=0，追加为小写字母的ascii码 

    }
    cout << str << endl;                //将字符串输出 
    return str;
}

int main()
{
    int len1,len2 ;/*= "ABCBDAB"*/
    string x,y ;/*= "BDCABA"*/
    cout << "请输入x的长度len1:" << endl;
    cin >> len1;
    gengerString(len1,x);
    cout << "请输入y的长度len2:" << endl;
    cin >> len2;
    gengerString(len2,y);
    vector< vector<int>> c;
    vector< vector<char>> b;

    auto t0 = std::chrono::steady_clock::now();
    lcsLength(x, y, c, b);
    print_lcs(b, x, len1, len2);
    cout << endl;
    auto t1 = std::chrono::steady_clock::now();
    auto d = std::chrono::duration_cast<std::chrono::nanoseconds>(t1 - t0);
    cout << "time cost:" << d.count() << "ns" << endl;

    cout << endl << "长度为：" << c[len1][len2] << endl;
}