描述下列代码的逻辑：#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

typedef struct Cell {
    int id;//信号小区的id（文件索引）
    double strength;//信号小区的强度
} Cell;


void popShot(Cell *cellArray, int length) {
    struct Cell t;
    for (int i = 0; i < length; ++i) {
        for (int j = 0; j < i; ++j) {
            if (cellArray[i].strength > cellArray[j].strength) {
                t = cellArray[i];
                cellArray[i] = cellArray[j];
                cellArray[j] = t;
            }
        }
    }
}

FILE *fileOpener(int index) {
    int markLength = 1;
    int ci = index;
    while (ci / 10 != 0) {
        ci /= 10;
        markLength++;
    }//计算当前标志的位数
    ci = index;
    char fileEnd[markLength + 1];
    char fileName[] = "D:\\data\\data";
    fileEnd[markLength] = 0;
    for (int j = markLength - 1; j >= 0; --j) {
        fileEnd[j] = ci % 10 + '0';
        ci /= 10;
    }//标记转化为string
    fileEnd[markLength] = 0;
//    printf("file end = %s\n",fileEnd);
    strcat(fileName, fileEnd);
    strcat(fileName, ".txt");//拼接文件名
    return fopen(fileName, "r");//打开文件
}

struct Cell *cellArrayFactory(int startMark, int endMark) {//读取并转化data的数据
    struct Cell *cells = (Cell *) malloc((endMark - startMark + 1) * sizeof(struct Cell));//声明结构体数组
    for (int i = startMark; i <= endMark; ++i) {//遍历stark-endMark的所有文件
        FILE *curFile = fileOpener(i);
        char cellDataFront[31];
        char cellDataNext[31];
        double res = 0;
        while (fscanf(curFile, "%s\n%s", cellDataFront, cellDataNext) == 2) {//如果可以正常的读取到两个数据
            //信号强度计算
            float dataFront = atof(cellDataFront);
            float dataNext = atof(cellDataNext);
            res += sqrt(dataFront * dataFront + dataNext * dataNext);
        }
        cells[i - startMark].strength = res;//计算平方
        cells[i - startMark].id = i;
        fclose(curFile);
    }
    popShot(cells, endMark - startMark + 1);
    return cells;
}

float analyzePss(int indexOfData, int indexOfPss) {
    float **rawData = (float **) malloc(2 * sizeof(float));
    rawData[0] = (float *) malloc(15000 * sizeof(float));
    rawData[1] = (float *) malloc(15000 * sizeof(float));

    float **pss = (float **) malloc(2 * sizeof(float));
    pss[0] = (float *) malloc(15000 * sizeof(float));
    pss[1] = (float *) malloc(15000 * sizeof(float));
    //循环三次PSS文件
    char fileHeader[] = "D:\\data\\";
    char fileName[] = "PSS1.txt";
    fileName[3] = indexOfPss + '0';
    strcat(fileHeader, fileName);
    FILE *pssFile = fopen(fileHeader, "r");
    char priorString[31];
    char nextString[31];
    int markOfPss = 0;
    if (pssFile == NULL) {
        printf("file not find\n");
    }
    while (fscanf(pssFile, "%s\n%s", priorString, nextString) == 2) {
        pss[0][markOfPss] = atof(priorString);
        pss[1][markOfPss] = atof(nextString);
        markOfPss++;
    }
    fclose(pssFile);
    //接下来计算滑动相关性
    //首先读取全部的data进入数组
    FILE *dataFile = fileOpener(indexOfData);
    int markOfRawData = 0;
    if (dataFile == NULL) {
        printf("data file no find\n");
    }
    while (fscanf(dataFile, "%s\n%s", priorString, nextString) == 2) {
        rawData[0][markOfRawData] = atof(priorString);
        rawData[1][markOfRawData] = atof(nextString);
        markOfRawData++;
    }
    //读取完毕，开始计算滑动相关性
    float max = 0;
    for (int j = 0; j < markOfRawData - markOfPss; ++j) {
        float total = 0;
        for (int k = 0; k < markOfPss; ++k) {
            total += rawData[0][k + j] * pss[0][k] + rawData[1][k + j] * pss[1][k];
        }
        if (total > max) {
            max = total;
        }
    }
//    printf("%lf", max);
    return max;
}

int main() {
    int startMark = 0;
    int endMark = 47;
    struct Cell *cells = cellArrayFactory(startMark, endMark);
    for (int i = 0; i < endMark - startMark + 1; ++i) {
        printf("Cell id = %d, Strength = %lf\n", cells[i].id, cells[i].strength);
    }

    for (int i = 0; i < 3; ++i) {
        float max = 0;
        int index = 0;
        for (int j = 0; j < endMark - startMark + 1; ++j) {
            float res = analyzePss(cells[j].id, i);
            if (res > max) {
                max = res;
                index = cells[j].id;
            }
        }
        printf("PSS%d, best cell is data%d, strength = %lf\n", i, index, max);
    }
}