記錄用. 用二元搜尋找upperbound和lowerbound.

例如:
0 1 2 3 4 5 6 7 8 9 10
----------------------------
0 0 1 1 1 2 2 2 2 3 3

要搜尋出從2~4都是1.

int findUpper1(int *pNum,int upperBound,int lowerBound,int n)
{
    int middle;

    if (pNum[upperBound]==n)
        return upperBound;
    while (upperBound + 1 < lowerBound) {
        middle = (upperBound + lowerBound) / 2;
        if (pNum[middle] < n) {
            upperBound = middle ;
        } else if (pNum[middle] > n) {
            lowerBound = middle ;
        } else if (pNum[middle] == n) {
            lowerBound = middle;
        }
    }
    if (pNum[lowerBound] == n)
        return lowerBound;
    return -1;
}


int findLower1(int *pNum,int upperBound,int lowerBound,int n)
{
    int middle;
    if (pNum[lowerBound]==n)
        return lowerBound;
    while (upperBound + 1 < lowerBound) {
        middle = (upperBound + lowerBound) / 2;
        if (pNum[middle] > n) {
            lowerBound = middle ;
        } else if (pNum[middle] == n) {
            upperBound = middle;
        } else {
            upperBound = middle ;
        }
    }
    if (pNum[upperBound] == n)
        return upperBound;
    return -1;
}

int findUpperLower1(int *pNum,int upperBound,int lowerBound,int n, int *u,int *l)
{
    int lower=lowerBound;
    int middle;
    *u=*l=-1;
    if (pNum[upperBound]==n) {
        *u = upperBound;
    } else {
        while (upperBound + 1 < lowerBound) {
            middle = (upperBound + lowerBound) / 2;
            if (pNum[middle] < n) {
                upperBound = middle ;
            } else if (pNum[middle] > n) {
                lower=lowerBound = middle ;
            } else if (pNum[middle] == n) {
                lowerBound = middle;
            }
        }
        if (pNum[lowerBound] == n) {
            *u = lowerBound;
        } else {
            return -1;
        }
    }
    if (*u == -1)
        return -1;
    upperBound = *u;
    lowerBound=lower;
    if (pNum[lowerBound]==n) {
        *l=lowerBound;
        return 0;
    }
    while (upperBound + 1 < lowerBound) {
        middle = (upperBound + lowerBound) / 2;
        if (pNum[middle] > n) {
            lowerBound = middle ;
        } else if (pNum[middle] == n) {
            upperBound = middle;
        } else {
            upperBound = middle ;
        }
    }
    if (pNum[upperBound] == n) {
        *l=upperBound;
        return 0;
    }
    return -1;
}