UVA 537 Artificial Intelligence?

每组输入一句话，包含P，U，I中的两个，求另一个，注意单位。

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<vector>
#include<cmath>
///LOOP
#define REP(i, n) for(int i = 0; i < n; i++)
#define FF(i, a, b) for(int i = a; i < b; i++)
#define FFF(i, a, b) for(int i = a; i <= b; i++)
#define FD(i, a, b) for(int i = a - 1; i >= b; i--)
#define FDD(i, a, b) for(int i = a; i >= b; i--)
///INPUT
#define RI(n) scanf("%d", &n)
#define RII(n, m) scanf("%d%d", &n, &m)
#define RIII(n, m, k) scanf("%d%d%d", &n, &m, &k)
#define RIV(n, m, k, p) scanf("%d%d%d%d", &n, &m, &k, &p)
#define RV(n, m, k, p, q) scanf("%d%d%d%d%d", &n, &m, &k, &p, &q)
#define RFI(n) scanf("%lf", &n)
#define RFII(n, m) scanf("%lf%lf", &n, &m)
#define RFIII(n, m, k) scanf("%lf%lf%lf", &n, &m, &k)
#define RFIV(n, m, k, p) scanf("%lf%lf%lf%lf", &n, &m, &k, &p)
#define RS(s) scanf("%s", s)
///OUTPUT
#define PN printf("\n")
#define PI(n) printf("%d\n", n)
#define PIS(n) printf("%d ", n)
#define PS(s) printf("%s\n", s)
#define PSS(s) printf("%s ", n)
///OTHER
#define PB(x) push_back(x)
#define CLR(a, b) memset(a, b, sizeof(a))
#define CPY(a, b) memcpy(a, b, sizeof(b))
#define display(A, n, m) {REP(i, n){REP(j, m)PIS(A[i][j]);PN;}}

using namespace std;
typedef long long LL;
typedef pair<int, int> P;
const int MOD = 1000000;
const int INFI = 1e9 * 2;
const LL LINFI = 1e17;
const double eps = 1e-6;
const double pi = acos(-1.0);
const int N = 1111;
const int M = 33;
const int move[8][2] = {0, 1, 0, -1, 1, 0, -1, 0, 1, 1, 1, -1, -1, 1, -1, -1};

char s
;

int main()
{
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);

int n, t, l;
double P, U, I, a, k;
RI(n);
getchar();
FFF(cas, 1, n)
{
gets(s);
printf("Problem #%d\n", cas);
P = U = I = -1;
l = strlen(s);
REP(i, l)
{
if(s[i] == '=')
{
t = i - 1;
i++;
a = 0;
while(isdigit(s[i]))a = a * 10 + s[i++] - '0';
if(s[i] == '.')
{
k = 10.0;
i++;
while(isdigit(s[i]))a += (s[i++] - '0' + 0.0) / k, k *= 10.0;
}
if(s[i] == 'M')a *= 1000000.0;
else if(s[i] == 'k')a *= 1000.0;
else if(s[i] == 'm')a /= 1000.0;
if(s[t] == 'P')P = a;
else if(s[t] == 'U')U = a;
else if(s[t] == 'I')I = a;
}
}
if(P == -1)printf("P=%.2lfW\n\n", U * I);
else if(U == -1)printf("U=%.2lfV\n\n", P / I);
else if(I == -1)printf("I=%.2lfA\n\n", P / U);
}
return 0;
}