题目：

题解：

int evalRPN(char** tokens, int tokensSize) {int n = tokensSize;int stk[(n + 1) / 2];memset(stk, 0, sizeof(stk));int index = -1;for (int i = 0; i < n; i++) {char* token = tokens[i];if (strlen(token) > 1 || isdigit(token[0])) {index++;stk[index] = atoi(token);} else {switch (token[0]) {case '+':index--;stk[index] += stk[index + 1];break;case '-':index--;stk[index] -= stk[index + 1];break;case '*':index--;stk[index] *= stk[index + 1];break;case '/':index--;stk[index] /= stk[index + 1];break;}}}return stk[index];
}