商汤科技笔试算法题（手写卷积）

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#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
int main() {
    int M, N;
    int tmparr;
    cin >> M >> N;
    vector<vector<int> > array(N, vector<int>(M, 0));
    for(int i = 0; i < N; ++i) {
        for(int j = 0; j < M; ++j) {
            cin >> tmparr;
            array[i][j] = tmparr;
        }
    }
    cout << "array end" << endl;
    int W, H;
    double tmpfilter;
    cin >> W >> H;
    vector<vector<double> > filter(H, vector<double>(W, 0));
    for(int i = 0; i < H; ++i) {
        for(int j = 0; j < W; ++j) {
            cin >> tmpfilter;
            filter[i][j] = tmpfilter;
        }
    }
    cout << "filter end" << endl;
    //vector<vector<unsigned char> > res(N, vector<unsigned char>(M, 0));
    double tmp;
    int top = -(H-1)/2;
    int left = -(W-1)/2;
    for(int i = 0; i < N; ++i) {
        for(int j = 0; j < M; ++j) {
            tmp = 0;
            int boxtop = i + top;
            int boxleft = j + left;
            for(int k = 0; k < H; ++k) {
                for(int l = 0; l < W; ++l) {
                    int tmpboxtop = boxtop + k;
                    int tmpboxleft = boxleft + l;
                    if (tmpboxtop < 0) tmpboxtop = -tmpboxtop;
                    if (tmpboxtop >= N) tmpboxtop = 2*N - 2 - tmpboxtop;
                    if (tmpboxleft < 0) tmpboxleft = - tmpboxleft;
                    if (tmpboxleft >= M) tmpboxleft = 2*M - 2 - tmpboxleft;
                    //cout << "tmpboxtop = " << tmpboxtop << endl;
                    //cout << "tmpboxleft = " << tmpboxleft << endl;
                    //cout << "k = " << k << endl;
                    //cout << "l = " << l << endl;
                    //cout << "array[tmpboxtop][tmpboxleft] = " << array[tmpboxtop][tmpboxleft] << endl;
                    //cout << "filter[k][l] = " << filter[k][l] << endl;
                    tmp += array[tmpboxtop][tmpboxleft] * filter[k][l];
                }
            }
            //res[i][j] = (unsigned char)tmp;
            cout << tmp << " ";
        }
        cout << endl;
    }
    system("pause");
}

padding填充后并same卷积的大体思路如上，然而题目还考了个用unsigned char存储原始图片的像素值（节省空间），在相乘的时候需要数据的转换，此代码直接用Int类型代替。