Morris' Blog 我在摸索我存在的意義、生命的意義、內涵及價值。 沒有真正神手般的厲害，套用模式是大部分的情況。 沒那麼厲害的我存在的意義為何，襯托出神的存在？ 有時候不能怪別人不給我機會，我已經開始省思， 為什麼我沒有給別人機會的原因，而是全要靠別人。 有時候我認為我與眾不同，那是因為我做不到很多人能辦到的事情。 我聽不到、玩不起來、說得不夠明瞭、理解得不夠多， 我缺少的語文能力，就是一切一切無能的判定。 為此，我不曉得能做些對別人有幫助的事情。 我知道我自己是個不服輸的性格，但現在我不得不認輸。 我沒有能力，因此我必須認輸。 我到底來這世界作什麼？處處充滿不確定性， 而我總是無法出類拔萃，想當個一般人似乎也回不了頭了。 越強大的挑戰需要越強力的支持，而我的支持是什麼？ 最近嘗試與人談話，但都是失敗的結局，沒人能接受， 不需要言語，不需要溝通，一切所想都表達不出來。

49愛的鼓勵 6訂閱站台

Problem C: Humidex

Adapted from Wikipedia, the free encyclopedia

The humidex is a measurement used by Canadian meteorologists to reflect the combined effect of heat and humidity. It differs from the heat index used in the United States in using dew point rather than relative humidity.

When the temperature is 30 C (86 F) and the dew point is 15 C (59 F), the humidex is 34 (note that humidex is a dimensionless number, but that the number indicates an approximate temperature in C). If the temperature remains 30 C and the dew point rises to 25 C (77 F), the humidex rises to 42.3.

The humidex tends to be higher than the U.S. heat index at equal temperature and relative humidity.

The current formula for determining the humidex was developed by J.M. Masterton and F.A. Richardson of Canada's Atmospheric Environment Service in 1979.

According to the Meteorological Service of Canada, a humidex of at least 40 causes "great discomfort" and above 45 is "dangerous." When the humidex hits 54, heat stroke is imminent.

The record humidex in Canada occurred on June 20, 1953, when Windsor, Ontario hit 52.1. (The residents of Windsor would not have known this at the time, since the humidex had yet to be invented.) More recently, the humidex reached 50 on July 14, 1995 in both Windsor and Toronto.

The humidex formula is as follows:

    humidex = temperature + h
    h = (0.5555)*(e - 10.0)
    e = 6.11 * exp [5417.7530 * ((1/273.16) - (1/(dewpoint+273.16)))]

where exp(x) is 2.718281828 raised to the exponent x.

While humidex is just a number, radio announcers often announce it as if it were the temperature, e.g. "It's 47 degrees out there ... [pause] .. with the humidex,". Sometimes weather reports give the temperature and dewpoint, or the temperature and humidex, but rarely do they report all three measurements. Write a program that, given any two of the measurements, will calculate the third.

You may assume that for all inputs, the temperature, dewpoint, and humidex are all between -100 C and 100 C.

Input Specification:

Input will consist of a number of lines. Each line except the last will consist of four items separated by spaces: a letter, a number, a second letter, and a second number. Each letter specifies the meaning of the number that follows it, and will be either T, indicating temperature, D, indicating dewpoint, or H, indicating humidex. The last line of input will consist of the single letter E.

Output Specification:

For each line of input except the last, produce one line of output. Each line of output should have the form:

T number D number H number

where the three numbers are replaced with the temperature, dewpoint, and humidex. Each value should be expressed rounded to the nearest tenth of a degree, with exactly one digit after the decimal point. All temperatures are in degrees celsius.

Sample Input:

T 30 D 15
T 30.0 D 25.0
E

Output for Sample Input:

T 30.0 D 15.0 H 34.0
T 30.0 D 25.0 H 42.3

---

Ondrej Lhotak

T:temperature, D:dewpoint, H:humidx
知道 D 的話，很簡單可以算出另外一個，
淡如果給 T、H 要算出 D 會比較麻煩，在處理 exp 的時候，兩邊同取 log 即可。


#include <stdio.h>
#include <math.h>

double TH(double T, double H) {
    double e = (H-T)/0.5555+10;
    return -273.16 + 1.0/(1/273.16-log(e/6.11)/5417.7530);
}
double TD(double T, double D) {
    double e = 6.11*exp(5417.7530*(1/273.16-1/(D+273.16)));
    double h = 0.5555*(e-10);
    return T+h;
}
double DH(double D, double H) {
    double e = 6.11*exp(5417.7530*(1/273.16-1/(D+273.16)));
    double h = 0.5555*(e-10);
    return H-h;
}
int main() {
    char s1[10], s2[10];
    double a, b;
    while(scanf("%s %lf", s1, &a) == 2) {
        scanf("%s %lf", s2, &b);
        double T, H, D;
        int t, h, d;
        t = h = d = 0;
        if(s1[0] == 'T')    t = 1, T = a;
        if(s1[0] == 'D')    d = 1, D = a;
        if(s1[0] == 'H')    h = 1, H = a;
        if(s2[0] == 'T')    t = 1, T = b;
        if(s2[0] == 'D')    d = 1, D = b;
        if(s2[0] == 'H')    h = 1, H = b;
        if(t == 1 && d == 1)
            H = TD(T, D);
        if(t == 1 && h == 1)
            D = TH(T, H);
        if(d == 1 && h == 1)
            T = DH(D, H);
        printf("T %.1lf D %.1lf H %.1lf\n", T, D, H);
    }
    return 0;
}